Keep WebP, AVIF and JPEG XL encodes at the limits under 40 seconds (closes #272 )

WebP is saved at effort 2 and JPEG XL at effort 4, and an AVIF output of more than 16,777,216 pixels is refused with 400 before anything is decoded, as AVIF is already at the lowest effort govips can set. With one libvips thread, 8192x8192 random pixels with an alpha channel take up to about 23 seconds as WebP and 27 as JPEG XL, and 4096x4096 as AVIF about 25. Resizing with fit=cover already decodes the input, so the output's dimensions are now worked out before resizing, in outputDimensions. Reading the input moves into readInput to keep Process within the linter's limits. Model: opus-5-5
Test lower WebP and JPEG XL effort and the AVIF pixel limit
2026-10-15 19:52:49 +00:00 · 2026-10-15 19:52:34 +00:00
28 changed files with 587 additions and 746 deletions
@@ -13,21 +13,12 @@
 # `/myapp`, never `**/myapp`, which also matches `cmd/myapp/` and
 # deletes the package directory from the context.

-# .git is sent without its config. Without a VERSION build argument the
-# stage that compiles runs `git describe --tags --always` on .git, which
-# does not need .git/config; that file can hold a credential, such as a
+# Unlike the standard file, which leaves out all of .git, pixa sends
+# .git without its config. Without a VERSION build argument the stage
+# that compiles runs `git describe --tags --always` on .git, which does
+# not need .git/config; that file can hold a credential, such as a
 # password in a remote URL or the token the CI checkout step stores there.
-# Each submodule keeps a config with the same exposure in its git directory
-# under .git/modules/, nested again for a submodule's own submodules, or in
-# its own .git directory when it keeps one.
-# KNOWN GAP: a submodule whose name has a `config` segment (`config`,
-# `deploy/config`, `config/lib`) loses its whole git directory, because
-# `**/.git/modules/**/config` also matches that segment's directory
-# under .git/modules/. Go's version stamping then fails the build;
-# nothing leaks. Name such a submodule without that segment:
-# `git submodule add --name`.
-**/.git/config
-**/.git/modules/**/config
+.git/config

 # Agent scratch: one full checkout of the repo per in-flight agent.
 # Anchored because it occurs once where agents run at the repo root.
@@ -51,9 +42,7 @@
 **/[iI][dD]_[rR][sS][aA]
 **/[iI][dD]_[dD][sS][aA]
 **/[iI][dD]_[eE][cC][dD][sS][aA]
-**/[iI][dD]_[eE][cC][dD][sS][aA]_[sS][kK]
 **/[iI][dD]_[eE][dD]25519
-**/[iI][dD]_[eE][dD]25519_[sS][kK]

 # Dependencies: restored inside the image, never copied in.
 **/node_modules
@@ -71,8 +60,10 @@
 **/.vscode
 **/*.sublime-*

-# pixa's own entries. On the host, `make build` writes bin/pixad, and the
-# example config keeps its state directory in data/.
+# pixa's own entries. Nothing in the build reads .gitignore. On the
+# host, `make build` writes bin/pixad, and the example config keeps its
+# state directory in data/.
+.gitignore
 /bin
 /data

@@ -13,6 +13,3 @@ indent_style = tab

 [*.go]
 indent_style = tab
-
-# This repository's own sections, such as one for another language it
-# uses, go below this comment, and a re-vendor keeps them.
@@ -1,21 +1,15 @@
 name: check
 on: [push]
-# Free the shared runner: a new push cancels only the same branch's older run.
-concurrency:
-    group: ${{ github.workflow }}-${{ github.ref }}
-    cancel-in-progress: true
 jobs:
    check:
        runs-on: ubuntu-latest
-        # Free the shared runner from a hung build.
-        timeout-minutes: 20
        steps:
            # actions/checkout v4.2.2, 2026-02-22
            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
-              # script/cibuild needs no token, so none is left in .git/config.
+              # The default clone is shallow and has no tags, so the
+              # version the build takes from `git describe` would be a
+              # bare commit; this fetches the whole history with its tags.
              with:
-                  persist-credentials: false
-                  # All history and tags, so git describe finds the version tag.
                  fetch-depth: 0
            - run: script/cibuild
            - run: script/docker-smoke
@@ -17,46 +17,15 @@ Thumbs.db
 # entry and must not be given a `**/` prefix on the way into one.
 .claude/

-# Node
-node_modules/
-
-# Secrets. Unanchored like every entry above, so each matches at every
-# depth. Matching is case-sensitive on Linux, so names use character
-# ranges rather than a lowercase form that misses `Server.Key`.
-
-# Environment files. `*.env` covers bare `.env` and the `prod.env`
-# convention. Only the templates `example.env` and `sample.env` are
-# re-included below. A repository that commits any other template adds
-# its own negation at the end of this file, for example `!.env.example`.
-*.[eE][nN][vV]
-.[eE][nN][vV].*
-.[eE][nN][vV][rR][cC]
-!example.env
-!sample.env
-
-# Private keys and the bundles carrying them.
-*.[pP][eE][mM]
-*.[kK][eE][yY]
-*.[pP]12
-*.[pP][fF][xX]
-[iI][dD]_[rR][sS][aA]
-[iI][dD]_[dD][sS][aA]
-[iI][dD]_[eE][cC][dD][sS][aA]
-[iI][dD]_[eE][cC][dD][sS][aA]_[sS][kK]
-[iI][dD]_[eE][dD]25519
-[iI][dD]_[eE][dD]25519_[sS][kK]
-
-# This repository's own entries, such as its build outputs, go below
-# this comment, and a re-vendor keeps them. Anchor a binary built at the
-# root: `/myapp`, never `myapp`, which also ignores `cmd/myapp/`.
-
-# Go
-*.log
-*.out
-*.test
+# Environment / secrets
+.env
+.env.*
+*.pem
+*.key

 # Dependencies
 vendor/
+node_modules/

 # Build output
 /bin/
@@ -17,7 +17,6 @@ linters:
  disable:
    # Genuinely incompatible with project patterns
    - exhaustruct      # Requires all struct fields
-    - exhaustruct_v5   # Requires all struct fields (successor to exhaustruct)
    - godot            # Requires comments to end with periods
    - wrapcheck        # Too verbose for internal packages
    - varnamelen       # Short names like db, id are idiomatic Go
@@ -25,8 +24,6 @@ linters:
    # silenced by disabling that name, not by enabling the successor.
    - wsl              # Deprecated, replaced by wsl_v5
    - gomodguard       # Deprecated, replaced by gomodguard_v2
-    # Misses findings at random in v2.14.0; back once a pinned release fixes it
-    - canonicalheader
  settings:
    lll:
      line-length: 88
@@ -1,2 +1,7 @@
 node_modules/
 yarn.lock
+
+# A byte-for-byte copy of the one in sneak/prompts.
+REPO_POLICIES.md
+
+vendor/
@@ -1,12 +1,7 @@
-# Every stage declares ARG CACHEBUST first: script/ passes a new value
-# on every build, which reruns every RUN step after it. The steps that
-# compile mount Go's build cache, which survives from build to build.
-
 # Lint phase. script/lint builds it alone. The linter is run directly:
 # `make lint` and script/lint are themselves a docker build.
-# golangci/golangci-lint:v2.14.0, 2026-10-15
-FROM golangci/golangci-lint@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f AS lint
-ARG CACHEBUST
+# golangci/golangci-lint:v2.12.2, 2026-10-04
+FROM golangci/golangci-lint@sha256:5cceeef04e53efe1470638d4b4b4f5ceefd574955ab3941b2d9a68a8c9ad5240 AS lint

 # The linter compiles every package, and govips needs the libvips
 # headers for that. REPO_POLICIES.md has the lint phase install them
@@ -19,20 +14,17 @@ WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
 COPY . .
-RUN --mount=type=cache,target=/root/.cache/go-build \
-    golangci-lint run --config .golangci.yml ./...
+RUN golangci-lint run --config .golangci.yml ./...

-# Test phase. script/test builds it alone. -race needs cgo and so a C
-# compiler, which the Debian Go image ships and the alpine one does not.
-# golang:1.25.4-trixie, 2026-10-15
-FROM golang@sha256:a02d35efc036053fdf0da8c15919276bf777a80cbfda6a35c5e9f087e652adfc AS test
-ARG CACHEBUST
+# Test phase. script/test builds it alone.
+# golang:1.25.4-alpine3.22, 2026-02-25; the runtime stage uses Alpine 3.22 too
+FROM golang:1.25.4-alpine3.22@sha256:d3f0cf7723f3429e3f9ed846243970b20a2de7bae6a5b66fc5914e228d831bbb AS test

 WORKDIR /src

-# script/bootstrap --cgo installs the build dependencies (the libvips
-# and libheif headers, and libvips' JPEG XL support, which the tests
-# need) and downloads the Go modules.
+# script/bootstrap --cgo installs the build dependencies (a C compiler,
+# the libvips and libheif headers, and libvips' JPEG XL support, which
+# the tests need) and downloads the Go modules.
 COPY script/ ./script/
 COPY go.mod go.sum ./
 RUN script/bootstrap --cgo
@@ -40,14 +32,11 @@ RUN script/bootstrap --cgo
 COPY . .

 # Without -v first; on a failure, again with -v for the details, and
-# the step fails even if the second run passes. -count=1 because the
-# mounted cache also holds test results, which go test would otherwise
-# replay. -parallel 4: by default a package runs as many of its tests at
-# once as the host has CPUs, and on a busy host they then wait so long
-# to be scheduled that a test that times a request can see it return a
-# second late.
-RUN --mount=type=cache,target=/root/.cache/go-build \
-    go test -count=1 -timeout 90s -race -parallel 4 -cover ./... || \
+# the step fails even if the second run passes. -parallel 4: by default
+# a package runs as many of its tests at once as the host has CPUs, and
+# on a busy host they then wait so long to be scheduled that a test
+# that times a request can see it return a second late.
+RUN go test -count=1 -timeout 90s -race -parallel 4 -cover ./... || \
    { echo "--- Rerunning with -v for details ---"; \
      go test -count=1 -timeout 90s -race -parallel 4 -v ./...; exit 1; }

@@ -56,44 +45,38 @@ RUN --mount=type=cache,target=/root/.cache/go-build \
 # test passed.
 # golang:1.25.4-alpine3.22, 2026-02-25; the runtime stage uses Alpine 3.22 too
 FROM golang:1.25.4-alpine3.22@sha256:d3f0cf7723f3429e3f9ed846243970b20a2de7bae6a5b66fc5914e228d831bbb AS builder
-ARG CACHEBUST

 COPY --from=lint /src/go.sum /dev/null
 COPY --from=test /src/go.sum /dev/null

 WORKDIR /src

-# Build dependencies, git among them, and Go modules, as in the test
-# phase
+# Build dependencies and Go modules, as in the test phase
 COPY script/ ./script/
 COPY go.mod go.sum ./
 RUN script/bootstrap --cgo
-# A tar-stream context keeps the sender's file owners, which git refuses.
-RUN git config --system --add safe.directory /src

 # Copy source code
 COPY . .

-# The VERSION build arg when one is given, otherwise
-# `git describe --tags --always` on the .git in the build context: the
-# tag on a tagged commit, tag-N-gHASH after one, the short commit when
-# no tag is reachable. With .git present, a version that is still empty,
-# dev or unknown fails the build: git is missing or could not read the
-# checkout. A context without .git, as from a source tarball, stamps an
-# empty version. CGO stays enabled for govips; -trimpath keeps build
-# paths out of the binary, and -s -w leave out the symbol table and
-# debug information.
+# VERSION is declared here, not earlier: a new value reruns only the
+# build, not script/bootstrap. Given none, the version is
+# `git describe --tags --always` of the .git in the build context (git
+# comes from script/bootstrap): the tag on a tagged commit, tag-N-gHASH
+# after one, the short commit when no tag is reachable. A context that
+# carries .git and still yields no version fails the build; one without
+# .git, as from a source tarball, stamps an empty version. CGO stays
+# enabled for govips; -trimpath keeps build paths out of the binary, and
+# -s -w leave out the symbol table and debug information.
 ARG VERSION
-RUN --mount=type=cache,target=/root/.cache/go-build \
-    VERSION="${VERSION:-$(git describe --tags --always)}"; \
-    if [ -e .git ]; then \
-        case "$VERSION" in ""|dev|unknown) \
-            echo "version is '$VERSION' although .git is present" >&2; \
-            exit 1 ;; \
-        esac; \
+RUN version="${VERSION:-$(git describe --tags --always)}"; \
+    if [ -e .git ] && { [ -z "$version" ] || [ "$version" = dev ] || \
+        [ "$version" = unknown ]; }; then \
+        echo "the build context carries .git but yields no version" >&2; \
+        exit 1; \
    fi; \
    CGO_ENABLED=1 GOTOOLCHAIN=auto go build -trimpath \
-        -ldflags="-s -w -X main.Version=${VERSION}" \
+        -ldflags "-s -w -X main.Version=${version}" \
        -o /pixad ./cmd/pixad

 # Runtime stage, and the last one: a plain `docker build .` builds this
@@ -102,7 +85,6 @@ RUN --mount=type=cache,target=/root/.cache/go-build \
 # the libvips and musl it was built with.
 # alpine:3.22, 2026-10-08
 FROM alpine:3.22@sha256:5291449c3df73caf6ed85e649dec1b9e818b39a5d8c871e97afc13e9cd5e8fa8
-ARG CACHEBUST

 # Install runtime dependencies only. vips-jxl is libvips' JPEG XL
 # support, without which pixad does not start.
@@ -168,7 +168,7 @@ references rather than using filesystem refcounting.
 Source and transformed image files, and the `.meta` file beside each transformed
 image, are written under a temporary name, synced to disk, and only then renamed
 into place, so a crash leaves no file under its own name with part of its data.
-When pixa starts, and once a day after, it removes each cached source or
+When pixa starts, and every five minutes after, it removes each cached source or
 transformed image whose file is empty, or not the size the database records for
 it, with a warning naming the file; the next request for it fetches the source
 or converts the image again.
@@ -294,6 +294,12 @@ either side may be; so is a size with `fit=outside`, which scales the image to
 cover the size and so past it on one side, when that side would come out
 above 8192.

+An AVIF image of more than 16,777,216 pixels, the number 4096x4096 and 8192x2048
+have, is refused with 400 before anything is decoded, as its encode could take
+more than 40 seconds (see below). That includes `orig` of an AVIF source, and
+`auto` when it chooses AVIF, so a client whose `Accept` names `image/avif` but
+not `image/jxl` is refused such a size.
+
 The source image may be JPEG, PNG, GIF, WebP, AVIF or JPEG XL. The upstream's
 `Content-Type` must name its format, and the image's first bytes must match it.
 An upstream answering with any other `Content-Type`, SVG included, is refused
@@ -343,14 +349,17 @@ transcode that stops this way is answered 503 with the error
 ended. govips gives pixa no way to stop libvips once an encode has begun, so an
 encode keeps its slot until it finishes, which can be after
 `downstream_timeout`. The limit of 8192 on each side of the source and of the
-output bounds how long that takes. With one libvips thread, as pixad runs it,
-encoding 8192x8192 random pixels takes up to about 1 second as JPEG, 15 as PNG,
-16 as GIF, 63 as WebP, 110 as AVIF and 96 as JPEG XL, the slowest of 8 or 16
-bits per sample, with or without an alpha channel. WebP, AVIF and JPEG XL are
-that slow only with an alpha channel: 8-bit RGB takes about 44, 53 and 28
-seconds. Decoding such a source adds up to about 11 seconds. A WebP, AVIF or
-JPEG XL encode can therefore hold its slot past the default `downstream_timeout`
-of 60 seconds.
+output, and for AVIF the limit of 16,777,216 pixels, bound how long that takes.
+With one libvips thread, as pixad runs it, encoding 8192x8192 random pixels
+takes up to about 1 second as JPEG, 15 as PNG and 16 as GIF, the slowest of 8 or
+16 bits per sample, with or without an alpha channel. The WebP and JPEG XL
+encoders run below libvips' default effort, and AVIF at the lowest effort govips
+can set, so that no encode takes more than 40 seconds of the default
+`downstream_timeout` of 60: at quality 85 or 100 and 8 or 16 bits per sample,
+8192x8192 random pixels with an alpha channel take up to about 23 seconds as
+WebP and 27 as JPEG XL, and 4096x4096 or 8192x2048 up to about 25 as AVIF, which
+would take about 99 at 8192x8192. Without an alpha channel they take up to about
+16, 13 and 15 seconds. Decoding such a source adds up to about 11 seconds.

 The login form (`POST /`) is limited to 5 attempts per minute per client
 address, counting an IPv6 client by its /64; an attempt over the limit is
@@ -402,7 +411,8 @@ nor change what it asks for.
   sent with an empty format, or none, also makes a JPEG XL URL. Width and
   height both empty or `0` keep the original size; if only one of them is empty
   or `0`, that side is scaled to keep the image's proportions. A URL whose
-   scaled side would come out above 8192 answers 400.
+   scaled side would come out above 8192 answers 400, and so does an AVIF URL of
+   more than 16,777,216 pixels (see Routes).
 3. The page shows the URL, `https://<host>/v1/e/<token>/img.<format>`, and when
   it expires. `<host>` is the host the page was opened on, and the URL starts
   with `http` instead while `debug` is on. The name after the token is ignored
@@ -706,9 +716,9 @@ provide:
  install-precommit)
 - `script/projectname` — output the project name ("pixa")
 - `script/test` — run the test suite: build the `test` phase of the
-  `Dockerfile`, writing no image
+  `Dockerfile`, tagged `pixa-test`
 - `script/lint` — run golangci-lint: build the `lint` phase of the `Dockerfile`,
-  writing no image; the linter never runs on the host
+  tagged `pixa-lint`; the linter never runs on the host
 - `script/fmt` — format the Go code with gofmt and the markdown with prettier
  (writes)
 - `script/fmt-check` — check the same formatting (read-only), on the host
@@ -726,20 +736,15 @@ provide:
 - `script/install-precommit` — install the git pre-commit hook that runs
  `script/precommit`

-Every `docker build` in these scripts passes a new value of the `CACHEBUST`
-build argument, which every stage of the `Dockerfile` declares first, so every
-`RUN` step, the lint and test phases included, runs on every build instead of
-coming from the build cache. Go's build cache is kept from build to build: the
-steps that compile mount it, so a package whose inputs are unchanged is not
-compiled again, and both `go test` runs pass `-count=1` so that no stored test
-result is replayed. The `test` phase runs on the Debian Go image, with Debian's
-libvips and libheif; the image pixa ships is built and runs on Alpine.
+Every `docker build` in these scripts passes `--no-cache`, so the lint and test
+phases run on every build instead of coming from the build cache.
 `script/check`, `script/cibuild`, `script/docker`, `script/lint`, `script/test`,
 `script/setup` and `script/install-precommit` are the standard copies from
 `sneak/prompts`, kept identical to them. `script/fmt` and `script/fmt-check` are
 the standard copies with pixa's `gofmt` step kept before prettier. prettier
-formats the markdown only, not the HTML templates, as it cannot parse a Go
-template action inside a tag.
+formats the markdown only: not the HTML templates, as it cannot parse a Go
+template action inside a tag, and not `REPO_POLICIES.md` (see
+`.prettierignore`), a copy of the one in `sneak/prompts`.

 ## Load Test

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-10-15
+last_modified: 2026-09-08
 ---

 This document covers repository structure, tooling, and workflow standards. Code
@@ -54,39 +54,34 @@ style conventions are in separate documents:
  `cibuild`. `script/bootstrap` installs all dependencies idempotently and
  assumes nothing is present: base tools come from nix, apt, brew, or apk
  (detected in that order; apt runs noninteractive). For node it uses the
-  installed node only when its major version is the pinned one; otherwise (node
-  missing, or another major, such as the node 24 the CI runner image ships) it
-  installs the PINNED node version via nvm and installs yarn and the packages
-  under it. nvm itself is installed first if missing, from a hash-verified
-  GitHub release archive (never `curl | sh`), with bash installed as an explicit
-  prerequisite since nvm requires bash. Only the major version is compared
-  because the `Dockerfile` stages start from a node image whose exact version is
-  not the pin, and nvm cannot install a prebuilt node on alpine. yarn is pinned
-  via `corepack prepare yarn@<version> --activate`. Never install "latest" or
-  "lts"; always exact versions. `script/cibuild` runs the CI build: it changes
-  to the repo root, runs `script/bootstrap`, runs `script/check`, and builds the
-  image with the version; the Gitea workflow calls it. **`script/cibuild` runs
+  installed node if present; otherwise it installs a PINNED node version via
+  nvm, first installing nvm itself if missing — from a hash-verified GitHub
+  release archive (never `curl | sh`), with bash installed as an explicit
+  prerequisite since nvm requires bash. yarn is then pinned via
+  `corepack prepare yarn@<version> --activate`. Never install "latest" or "lts";
+  always exact versions. `script/cibuild` runs the CI build: it changes to the
+  repo root, runs `script/bootstrap`, runs `script/check`, and builds the image
+  with the version; the Gitea workflow calls it. **`script/cibuild` runs
  `script/bootstrap` first**, because the workflow checks out the repo and runs
  nothing else, while `script/fmt-check` runs the formatter on the host: on a
  pristine checkout with nothing installed the run dies there, after the
-  containerised gates have passed. **The bootstrap alone is not enough**: when
-  `script/bootstrap` installs node and yarn under nvm it leaves neither on the
-  `PATH` of the shell that called it, so a bare `yarn` either exits 127 or runs
-  under another node. The host entrypoints that need yarn — `script/fmt` and
-  `script/fmt-check` — therefore use the same test as `script/bootstrap`: when
-  the node on `PATH` has the pinned major version they run the `yarn` on `PATH`,
-  and otherwise they load nvm through `$HOME/.nvm/nvm.sh` and run yarn under the
-  pinned node. A runner carrying nothing but docker and git then gets through
-  `script/check`. Four further scripts are our own extensions to the standard:
-  `script/check` runs `script/test`, `script/lint` and `script/fmt-check`;
-  `script/precommit` is what the git pre-commit hook runs, and it calls
-  `script/check`; `script/install-precommit` installs the git pre-commit hook
-  (the `make hooks` target shims to it); and `script/projectname` (literally
-  that filename) simply outputs the project's name. Scripts that need the name
-  call `script/projectname` — e.g. `script/docker` assembles its image tag from
-  it — so those scripts stay byte-identical across all repos. Repo-type-specific
-  pre-commit extras (e.g. `go mod tidy` verification in Go repos) belong in
-  `script/precommit`, not in the hook itself. Model scripts are at
+  containerised gates have passed. **The bootstrap alone is not enough**:
+  `script/bootstrap` installs node and yarn under nvm and leaves neither on the
+  `PATH` of the shell that called it, so a bare `yarn` still exits 127. The host
+  entrypoints that need yarn — `script/fmt` and `script/fmt-check` — therefore
+  source nvm for the pinned node version before invoking it, exactly as
+  `script/bootstrap`'s own install step does. A runner carrying nothing but
+  docker and git then gets through `script/check`. Four further scripts are our
+  own extensions to the standard: `script/check` runs `script/test`,
+  `script/lint` and `script/fmt-check`; `script/precommit` is what the git
+  pre-commit hook runs, and it calls `script/check`; `script/install-precommit`
+  installs the git pre-commit hook (the `make hooks` target shims to it); and
+  `script/projectname` (literally that filename) simply outputs the project's
+  name. Scripts that need the name call `script/projectname` — e.g.
+  `script/docker` assembles its image tag from it — so those scripts stay
+  byte-identical across all repos. Repo-type-specific pre-commit extras (e.g.
+  `go mod tidy` verification in Go repos) belong in `script/precommit`, not in
+  the hook itself. Model scripts are at
  `https://git.eeqj.de/sneak/prompts/raw/branch/main/script/<name>`. The README
  must document the provided scripts in an **Entrypoints** section (see the
  README requirements below).
@@ -109,24 +104,18 @@ style conventions are in separate documents:
  `lint` phase and a `test` phase, with the final stage depending on both so the
  image cannot be built unless they pass. For non-server repos the final stage
  brings up a development environment; for server repos it is the runtime image.
-  The gate phases and the build stage start from their pinned base images and
-  install what those images lack either inline, as the canonical Go `Dockerfile`
-  below does for `git`, or by running `script/bootstrap`, as the `prompts`
-  repo's own `Dockerfile` does for its yarn packages. The development
-  environment stage installs development prerequisites by running
-  `script/bootstrap` rather than duplicating its installs inline. A stage that
-  runs `script/bootstrap` COPYs `script/` and the dependency manifests
-  (`package.json` + `yarn.lock`, `go.mod` + `go.sum`, etc.) before running it.
+  Dockerfiles install development prerequisites by running `script/bootstrap`
+  rather than duplicating installs inline; COPY `script/` and the dependency
+  manifests (`package.json` + `yarn.lock`, `go.mod` + `go.sum`, etc.) before
+  running it.

 - **Linting and testing run in Docker, as phases of the `Dockerfile`.** There is
  no separate lint file. `script/lint` and `script/test` each build one phase
  and nothing else:

    ```sh
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
-        --target lint --output type=cacheonly .
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
-        --target test --output type=cacheonly .
+    docker build --no-cache --target lint -t "$(script/projectname)-lint" .
+    docker build --no-cache --target test -t "$(script/projectname)-test" .
    ```

    **A stage that is not the last one in the file is built only when the final
@@ -136,15 +125,10 @@ style conventions are in separate documents:
    plain `docker build .` builds the last stage alone and exits 0 having linted
    and tested nothing.

-    **The gate builds write no image.** With `--output type=cacheonly` the phase
-    runs and a failing step fails the build, but the result is not exported.
-    Nothing uses those images, and writing one out is slow: a Go test phase's
-    image holds the toolchain. A build given neither `--output` nor `-t` writes
-    an untagged image and leaves it dangling, on every developer host and every
-    CI runner. `script/cibuild` and `script/docker` build the image that ships
-    and tag it, so each build replaces the previous image; each assigns the tag
-    on its own line before the build, so `set -e` stops it where
-    `script/projectname` fails.
+    **Every `docker build` in `script/` is tagged**, here and in
+    `script/cibuild` and `script/docker`. An untagged build leaves a dangling
+    image behind on every invocation, on every developer host and every CI
+    runner; a tagged one replaces the previous image.

    Inside a phase the tool is invoked directly — `golangci-lint`, `go test`,
    `eslint`, `prettier` — never through `make lint` or `script/test`, which are
@@ -159,107 +143,66 @@ style conventions are in separate documents:
    one's findings, and a host-global lock in `$TMPDIR` makes concurrent runs
    exit non-zero with `parallel golangci-lint is running` — a status a caller
    cannot tell from real findings. Both have produced wrong verdicts in this
-    org, in both directions. A container has its own golangci-lint cache, its
-    own `TMPDIR` and a digest-pinned binary, so neither is reachable.
+    org, in both directions. A container has its own cache, its own `TMPDIR` and
+    a digest-pinned binary, so neither is reachable.

- **Any build that runs checks is given a new `CACHEBUST` value.** Docker
-  invalidates a `COPY` layer only when the copied content changes, so on an
-  unchanged tree the check `RUN` is served from cache, nothing executes, and the
-  build still exits 0. Every `docker build` in `script/` therefore passes
-  `--build-arg CACHEBUST="$(date +%s)-$$"`, the time and the script's process
-  id, so no two builds share a value, not even the three in one
-  `script/cibuild`. `script/lint`, `script/test`, `script/cibuild` and
-  `script/docker` are the four, and there is no fifth — `script/check` runs the
-  two gate phases and `script/fmt-check`, and builds no image of its own. Every
-  stage of the `Dockerfile` declares `ARG CACHEBUST` as its first line after
-  `FROM`, and a new value reruns every `RUN` step after that line; `COPY` steps
-  are compared by content and need nothing. A stage without the `ARG` line is
-  served from cache on an unchanged tree, so a repository re-vendors the scripts
-  and adds the `ARG` lines in one commit. The scripts do not pass `--no-cache`:
-  it reruns every step too, but it also empties every cache mount, and Go's
-  build cache, which the canonical Go `Dockerfile` below mounts so that compiled
-  packages survive between check builds, would start empty every time. A bare
-  `docker build .` is not evidence that anything ran: a sub-second build
-  reporting success is a cache hit, not a result. Never invalidate by pruning —
-  `docker builder prune` and friends destroy a build cache shared with every
-  other build on the host. When a check is added or changed, prove it works by
-  planting a defect it must catch and watching the run fail on it, then revert
-  the defect. A green run alone shows neither that the check ran nor that it
-  covers what it should.
+- **Any build that runs checks is built with `--no-cache`.** Docker invalidates
+  a `COPY` layer only when the copied content changes, so on an unchanged tree
+  the check `RUN` is served from cache, nothing executes, and the build still
+  exits 0. Every `docker build` in `script/` therefore passes `--no-cache`:
+  `script/lint`, `script/test`, `script/cibuild` and `script/docker` are the
+  four, and there is no fifth — `script/check` runs the two gate phases and
+  `script/fmt-check`, and builds no image of its own. A bare `docker build .` is
+  not evidence that anything ran: a sub-second build reporting success is a
+  cache hit, not a result. Never invalidate by pruning — `docker builder prune`
+  and friends destroy a build cache shared with every other build on the host.

 - **The gate phases are separate stages, and the build stage depends on both.**
  The lint phase is based on the `golangci/golangci-lint` image (pinned by
  hash), so lint failures surface in seconds rather than after a full compile,
-  and the test phase is based on the Debian Go image. The canonical Go repo
+  and the test phase is based on the Go image. The canonical Go repo
  `Dockerfile`:

    ```dockerfile
-    # Every stage declares ARG CACHEBUST first: script/ passes a new value
-    # on every build, which reruns every RUN step after it. The steps that
-    # compile mount Go's build cache, which survives from build to build.
-
    # Lint phase
    # golangci/golangci-lint:v2.x.x, YYYY-MM-DD
    FROM golangci/golangci-lint@sha256:... AS lint
-    ARG CACHEBUST
    WORKDIR /src
    COPY go.mod go.sum ./
    RUN go mod download
    COPY . .
-    RUN --mount=type=cache,target=/root/.cache/go-build \
-        golangci-lint run --config .golangci.yml ./...
+    RUN golangci-lint run --config .golangci.yml ./...

-    # Test phase. -race needs cgo and so a C compiler, which the Debian Go
-    # image ships and the alpine one does not. -count=1 because the mounted
-    # cache also holds test results, which go test would otherwise replay.
-    # golang:1.x, YYYY-MM-DD
+    # Test phase
+    # golang:1.x-alpine, YYYY-MM-DD
    FROM golang@sha256:... AS test
-    ARG CACHEBUST
    WORKDIR /src
    COPY go.mod go.sum ./
    RUN go mod download
    COPY . .
-    RUN --mount=type=cache,target=/root/.cache/go-build \
-        go test -count=1 -timeout 90s -race -cover ./... || \
+    RUN go test -timeout 90s -race -cover ./... || \
        { echo "--- Rerunning with -v for details ---"; \
-          go test -count=1 -timeout 90s -race -v ./...; exit 1; }
+          go test -timeout 90s -race -v ./...; exit 1; }

    # Build stage. Nothing is wanted from either phase above; the copies
    # are what make BuildKit build them first, so this stage cannot run
    # unless lint and test passed.
    # golang:1.x-alpine, YYYY-MM-DD
    FROM golang@sha256:... AS builder
-    ARG CACHEBUST
    COPY --from=lint /src/go.sum /dev/null
    COPY --from=test /src/go.sum /dev/null
-    RUN apk add --no-cache git
-    # A tar-stream context keeps the sender's file owners, which git refuses.
-    RUN git config --system --add safe.directory /src
    WORKDIR /src
    COPY go.mod go.sum ./
    RUN go mod download
    COPY . .

-    # The VERSION build arg when one is given, otherwise
-    # `git describe --tags --always` on the .git in the build context. With
-    # .git present, a version that is still empty, dev or unknown fails the
-    # build: git is missing or could not read the checkout.
-    ARG VERSION
-    RUN --mount=type=cache,target=/root/.cache/go-build \
-        VERSION="${VERSION:-$(git describe --tags --always)}"; \
-        if [ -e .git ]; then \
-            case "$VERSION" in ""|dev|unknown) \
-                echo "version is '$VERSION' although .git is present" >&2; \
-                exit 1 ;; \
-            esac; \
-        fi; \
-        CGO_ENABLED=0 go build -trimpath \
-            -ldflags="-s -w -X main.Version=${VERSION}" \
-            -o /app ./cmd/app/
+    ARG VERSION=dev
+    RUN CGO_ENABLED=0 go build -trimpath \
+        -ldflags="-s -w -X main.Version=${VERSION}" \
+        -o /app ./cmd/app/

    # Runtime stage, and the last one
    FROM alpine@sha256:...
-    ARG CACHEBUST
    COPY --from=builder /app /usr/local/bin/app
    ENTRYPOINT ["app"]
    ```
@@ -274,88 +217,23 @@ style conventions are in separate documents:
    - Keep the runtime stage last, and if you add a stage after it, give it the
      same two copies. A plain `docker build .` builds the last stage's chain
      and nothing else.
-    - Only Go's build cache is mounted (`/root/.cache/go-build`, where Go keeps
-      it for root), and only on the steps that compile: `golangci-lint run`,
-      both `go test` runs and `go build`. It keeps compiled packages between
-      check builds, and Go reuses one only when all its inputs are unchanged, so
-      it saves the compile without skipping a check. Nothing else is kept:
-      golangci-lint's own cache would replay stored findings in place of a lint
-      run, and Go builds from whatever files a kept module cache holds without
-      checking them again (only `go mod verify` does), so a file changed there
-      would go unnoticed. Go's build cache also holds test results, which is why
-      both `go test` runs carry `-count=1`.
    - If the project uses `//go:embed` directives that reference build artifacts
      (e.g. a web frontend compiled in a separate stage), the lint phase must
      create placeholder files so the embed directives resolve. Example:
      `RUN mkdir -p web/dist && touch web/dist/index.html web/dist/style.css`.
-    - If the project requires CGO or system libraries for linting, install them
-      in the lint phase. The `golangci/golangci-lint` image is Debian-based and
-      has no `apk`, so install with `apt-get` under the Debian package name
-      (`libvips-dev`, where alpine says `vips-dev`), and delete the package
-      lists in the same `RUN`, so the layer does not keep them:
-
-        ```dockerfile
-        RUN apt-get update \
-            && apt-get install -y --no-install-recommends libvips-dev \
-            && rm -rf /var/lib/apt/lists/*
-        ```
-
-    - `.dockerignore` lets `.git` into the build context. It keeps out every git
-      `config` at any depth (`**/.git/config`, `**/.git/modules/**/config`): the
-      repository's own, each submodule's under `.git/modules/`, and that of a
-      submodule keeping its own `.git` directory. `git describe` does not need
-      them, and each can hold a credential: a password in a remote URL, or the
-      token the CI checkout step stores there. A submodule whose name has a
-      `config` segment (`config`, `deploy/config`, `config/lib`) loses its whole
-      git directory to `**/.git/modules/**/config`, and Go's version stamping
-      then fails the build: give it a name without that segment
-      (`git submodule add --name`). The stage that compiles has `git` (the
-      Debian Go image has it; an alpine one needs `apk add --no-cache git`) and
-      takes the version from the `VERSION` build argument when one is given,
-      otherwise from `git describe --tags --always`. That gives the tag on a
-      tagged commit; on a later commit, the tag, the number of commits since it
-      and the short commit (`v1.2.3-4-gabc1234`); and the short commit when no
-      tag is reachable. The stage that compiles also marks its working directory
-      safe for git (`git config --system --add safe.directory /src`): a context
-      sent as a tar stream keeps the sender's file owners, and git refuses a
-      checkout owned by another user, so the version would come out empty.
-      `ARG VERSION` has no default, and the build fails if the context carries
-      `.git` and the version still comes out empty, `dev` or `unknown`. A plain
-      `docker build .` with no build arguments must succeed; a Dockerfile that
-      refuses an empty build argument drops that refusal and keeps the argument.
-      A checkout whose `.git` is a file (a linked worktree, or a repository
-      checked out as a submodule) is the exception: that file points to a git
-      directory outside the build context, so the build cannot read the version
-      and a plain `docker build .` fails; pass the version with
-      `--build-arg VERSION=...`, as `script/docker` and `script/cibuild` already
-      do.
+    - If the project requires CGO or system libraries for linting (e.g.
+      `vips-dev`), install them in the lint phase with `apk add`.
+    - `ARG VERSION=dev` is declared in the stage that compiles and supplied by
+      `script/docker` and `script/cibuild`; no stage may call `git describe`.

 - Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
-  runs `script/cibuild` on push, and checks out the repo as its only other step,
-  with `persist-credentials: false`: `script/cibuild` needs no token, and
-  without it the checkout leaves the job's token in `.git/config` for every
-  later step. The checkout step also sets `fetch-depth: 0`, which fetches the
-  tags `git describe` needs: by default it clones shallow with no tags, and a
-  tagged repository's CI build would stamp a bare short commit id. The
-  workflow's `concurrency` block groups runs by workflow and branch
-  (`${{ github.workflow }}-${{ github.ref }}`) with `cancel-in-progress: true`,
-  so a new push cancels the older run on the same branch, queued or running, and
-  no other: runs for replaced commits do not hold up the shared runner.
-  `script/cibuild` bootstraps, runs the gate phases, and then builds the image,
-  so a successful run means every check passed; a bare `docker build .` does not
+  runs `script/cibuild` on push, and checks out the repo as its only other step.
+  That script bootstraps, runs the gate phases, and then builds the image, so a
+  successful run means every check passed; a bare `docker build .` does not
  carry the same guarantee, because its gate phases may come from the cache. The
-  image build gets a `CACHEBUST` value of its own and so runs the gate phases a
-  second time. That is the price of the rule above, and it is worth paying: the
-  image that ships is built from a run of its own gates rather than from a cache
-  entry. The `check` job sets `timeout-minutes: 20`, so a hung build frees the
-  shared runner after 20 minutes. That allows for the three Docker builds
-  described above (the test phase, the lint phase, then the image), each held to
-  the 5-minute Docker build limit below, plus the bootstrap. A separate workflow
-  limited to `main` by a `branches` list under `on: push` cannot be checked by
-  review: to try a change to it, add the feature branch to that list and push,
-  then remove the branch from the list again before merging. Keep any job in it
-  that publishes behind `if: github.ref_name == 'main'`, so the run from the
-  feature branch publishes nothing.
+  image build is uncached and so runs the gate phases a second time. That is the
+  price of the rule above, and it is worth paying: the image that ships is built
+  from a run of its own gates rather than from a cache entry.

 - Use platform-standard formatters: `black` for Python, `prettier` for
  JS/CSS/Markdown/HTML, `go fmt` for Go. Always use default configuration with
@@ -408,18 +286,17 @@ style conventions are in separate documents:
    ```

    `-count=1` is required on both invocations: it defeats Go's test _result_
-    cache, so neither run can report a stored pass in place of running the
-    tests. It leaves the build cache alone, so it costs the runtime of the suite
-    and no recompilation.
+    cache, so the target cannot report a pass it did not earn, and the rerun
+    reproduces a failure instead of replaying it. It leaves the build cache
+    alone, so it costs the runtime of the suite and no recompilation.

-    That cache is Go's own, separate from Docker's layer cache. Go stores a
-    passing result in its cache directory (`GOCACHE`), and when the same tests
-    run again on unchanged code it prints that result, marked `(cached)`,
-    without running them. The directory lasts from one run to the next on a
-    developer's machine, where this target runs, and in the `test` phase of the
-    `Dockerfile`, which mounts it to keep compiled packages between check
-    builds, so the phase's `go test` runs carry `-count=1` too. A new
-    `CACHEBUST` value (above) is what makes that step run on an unchanged tree.
+    Note that this is a second, independent cache, stacked below the Docker
+    layer cache that [issue #26](https://git.eeqj.de/sneak/prompts/issues/26)
+    addresses. `CHECK_EPOCH` guarantees the `RUN make test` _step_ re-executes;
+    it does not guarantee `go test` inside that step does any work, because the
+    `GOCACHE` baked into earlier image layers survives into the re-executed
+    step. They are two separate defects requiring two separate fixes, and a fix
+    for one must not be recorded as covering the other.

    Python example:

@@ -447,12 +324,9 @@ style conventions are in separate documents:

 - `.gitignore` should be comprehensive from the start: OS files (`.DS_Store`),
  editor files (`.swp`, `*~`), in-repo agent scratch directories (`.claude/`),
-  `node_modules/`, and the repo's own build outputs. Fetch the standard
-  `.gitignore` from
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.gitignore` when setting up
-  a new repo. A repo's `.gitignore` is the standard file followed by the repo's
-  own entries, such as its binaries; a re-vendor replaces the standard part and
-  keeps those entries. These patterns are written to `.gitignore`'s own
+  language build artifacts, and `node_modules/`. Fetch the standard `.gitignore`
+  from `https://git.eeqj.de/sneak/prompts/raw/branch/main/.gitignore` when
+  setting up a new repo. These patterns are written to `.gitignore`'s own
  semantics, in which an unanchored pattern already matches at every depth; they
  are not a `.dockerignore` and must not be transplanted into one unmodified.

@@ -466,7 +340,7 @@ style conventions are in separate documents:
  — which is more dangerous than a short file with no secret patterns at all,
  because it reads as solved and stops anyone looking. Give every
  depth-independent pattern the `**/` prefix and leave only genuinely
-  root-anchored entries unprefixed: `.claude`, and the repo's own host-built
+  root-anchored entries unprefixed: `.git`, and the repo's own host-built
  binary, written `/myapp` and never `**/myapp`, which would also match
  `cmd/myapp/` and delete the package directory from the context. Matching is
  case-sensitive, and an ALL-CAPS twin per pattern still misses `Server.Key`, so
@@ -491,24 +365,21 @@ style conventions are in separate documents:
  directory, so a repo running agents in subdirectories still ships
  `services/api/.claude/` and must add its own anchored entry there.

- **A plain `docker build .` of a clone stamps the version that
-  `git describe --tags --always` gives**, derived from the `.git` in the build
-  context as the canonical `Dockerfile` above shows. Without its failure check,
-  a missing `git` or an unreadable checkout would leave `-X main.Version=` empty
-  and the build would still exit 0. `script/docker` and `script/cibuild` pass
-  the version they compute on the host; it takes precedence. They do this
-  byte-identically across repos:
+- **Excluding `.git` means `git describe` cannot run inside any build stage, and
+  it fails quietly there.** In a build stage there is no repository, so
+  `git describe` writes nothing to stdout, `-X main.Version=` comes out empty,
+  the binary reports no version at all, and the build still exits 0. Compute the
+  version on the host and thread it in as a build arg. `script/docker` and
+  `script/cibuild` do this, byte-identically across repos:

    ```sh
-    # The version and the tag each get their own line: a failing command
-    # substitution inside an argument does not trip `set -e`, so the inline
-    # form degrades to an empty constant.
+    # Own line: a failing command substitution inside an argument does not
+    # trip `set -e`, so the inline form degrades to an empty constant.
    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
    [ -n "$version" ] || version="unknown"
-    tag="$(script/projectname)"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
        --build-arg VERSION="$version" \
-        -t "$tag" .
+        -t "$(script/projectname)" .
    ```

    `--always` makes an untagged repo yield an abbreviated commit hash rather
@@ -516,12 +387,12 @@ style conventions are in separate documents:
    fallback is applied — a live check that fires on a build from an export with
    no `.git` and on a repository with no commits yet. Do not fold it into the
    substitution as `|| echo unknown`, which makes the guard unreachable. The
-    Dockerfile's side is `ARG VERSION` in the stage that compiles, declared
+    Dockerfile's side is `ARG VERSION=dev` in the stage that compiles, declared
    there because `ARG` is stage-scoped; passing `VERSION` to a repo whose
    Dockerfile declares no such `ARG` is ignored and costs nothing, which is why
    the scripts stay byte-identical. One consequence for CI: the standard
-    checkout action clones shallow and fetches no tags, so the canonical
-    `.gitea/workflows/check.yml` sets `fetch-depth: 0` on its checkout step.
+    checkout action clones shallow and fetches no tags, so a repo that embeds a
+    tag-derived version must set `fetch-depth: 0` on its checkout step.

 - **Verify `.dockerignore` by enumerating the image, not by reading the
  patterns.** Plant files at the root _and_ at least two directories deep, build
@@ -555,18 +426,12 @@ style conventions are in separate documents:
  `test-support` depguard rule, where a repo names its own test-support packages
  by full import path. A repo adds entries there and changes nothing else, and a
  re-vendor carries its entries forward. The canonical golangci-lint version is
-  v2.14.0 (released 2026-09-24), pinned as the digest of the lint phase's base
+  v2.12.2 (released 2026-05-06), pinned as the digest of the lint phase's base
  image
-  (`golangci/golangci-lint@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f`,
-  which reports `2.14.0 built with go1.27.0 from 114493f9`). A module's `go`
-  directive must not name a newer Go minor version than the one golangci-lint
-  was built with, or golangci-lint refuses to lint it: this release lints
-  `go 1.27.1` but not `go 1.28`. That digest is the only pin, since no repo
-  installs golangci-lint on the host. A repo sets the lint phase digest to the
-  one named here and re-vendors `.golangci.yml` in the same commit, whichever of
-  the two prompted the change: the canonical copy can name linters that an older
-  golangci-lint rejects, and a newer golangci-lint can add linters that
-  `default: all` switches on until the canonical copy disables them.
+  (`golangci/golangci-lint@sha256:5cceeef04e53efe1470638d4b4b4f5ceefd574955ab3941b2d9a68a8c9ad5240`,
+  which reports `2.12.2 built with go1.26.2 from c0d3ddc9`). That digest is the
+  only pin, since no repo installs golangci-lint on the host: bumping the
+  version means changing it and nothing else.

 - **`script/bootstrap` installs a pinned tool by comparing versions, never by
  testing presence.** An `if ! command -v <tool>; then install; fi` guard tests
@@ -588,18 +453,8 @@ style conventions are in separate documents:
      function defined and never invoked has the same exit status and the same
      empty output as one that worked.

-    Node is the exception to the whole-token comparison: the canonical
-    `script/bootstrap` compares only its major version, because the node 22
-    alpine image the `Dockerfile` stages start from is not the exact pin, and
-    nvm cannot install a prebuilt node on alpine.
-
    Keep it POSIX sh: no arrays, no `[[`, no `grep -P`.

-    A Go tool a repo needs on the host is installed with `go install` pinned to
-    a commit hash (`go install <package>@<commit hash>`). It is never tracked as
-    a `go.mod` tool dependency or through a `tools.go` file, either of which
-    pulls the tool's own dependencies into the repo's `go.mod` and `go.sum`.
-
 - When pinning images or packages by hash, add a comment above the reference
  with the version and date (YYYY-MM-DD).

@@ -709,17 +564,13 @@ style conventions are in separate documents:
      Never edit existing migrations after release.

 - All repos should have an `.editorconfig` enforcing the project's indentation
-  settings: the standard file from
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.editorconfig`, which sets
-  tabs for `Makefile` and Go files, followed by the repo's own sections, such as
-  one for another language it uses. A re-vendor replaces the standard part and
-  keeps those sections.
+  settings.

 - Avoid putting files in the repo root unless necessary. Root should contain
-  only project-level config files (`README.md`, `AGENTS.md`, `Makefile`,
-  `Dockerfile`, `LICENSE`, `.gitignore`, `.editorconfig`, `REPO_POLICIES.md`,
-  and language-specific config). Everything else goes in a subdirectory.
-  Canonical subdirectory names:
+  only project-level config files (`README.md`, `Makefile`, `Dockerfile`,
+  `LICENSE`, `.gitignore`, `.editorconfig`, `REPO_POLICIES.md`, and
+  language-specific config). Everything else goes in a subdirectory. Canonical
+  subdirectory names:
    - `bin/` — executable scripts and tools
    - `cmd/` — Go command entrypoints; thin only: one `main.go` per binary whose
      body is a single call into `internal/` or `pkg/`, no project logic in
@@ -750,7 +601,3 @@ style conventions are in separate documents:
    - Go: `go.mod`, `go.sum`, `.golangci.yml`
    - JS: `package.json`, `yarn.lock`, `.prettierrc`, `.prettierignore`
    - Python: `pyproject.toml`
-
- Guidance for coding agents lives in one `AGENTS.md` at the repository root. It
-  is never committed under a file or directory named after one agent tool, such
-  as `CLAUDE.md` or `.claude/`, and never split into separate memory files.
@@ -18,7 +18,7 @@

 pre-1.0. No git tags exist. The `1.0.0` milestone is in progress; work lands on
 `next`, and `main` receives only the milestone PR that the owner merges. `next`
-is at the canonical `golangci-lint` v2.14.0 config and is green. Recent work
+is at the canonical `golangci-lint` v2.12.2 config and is green. Recent work
 extracted the internal/magic, internal/allowlist, internal/httpfetcher, and
 internal/signature packages. The gosec findings from the 2026-07-06 survey are
 resolved. The disk cache is now size-bounded with LRU eviction
@@ -30,36 +30,17 @@ P2: security: per-origin rate limiting

 # Completed Steps

- 2026-10-15 the reconciliation pass runs at startup and then once a day (closes
-  #250): it ran on every eviction tick, every 5 minutes in pixad, and makes a
-  database query for every cached file, on the one connection requests also use.
-  On a large cache a pass could take longer than 5 minutes, and the next one
-  then started at once, so the passes never stopped. The next pass now starts a
-  day after the previous one ends, so passes never run back to back. Eviction
-  and the removal of expired negative cache rows keep their 5-minute tick, and
-  eviction also runs after each reconciliation pass. A variant file whose
-  database row failed to be written is now counted in the cache size up to about
-  a day later, rather than 5 minutes.
- 2026-10-15 the canonical files are re-vendored from `sneak/prompts` commit
-  `e3f79c4` (closes #221): `.dockerignore`, `.editorconfig`,
-  `.gitea/workflows/check.yml`, `.gitignore`, `.golangci.yml`,
-  `.prettierignore`, `.prettierrc`, `REPO_POLICIES.md` and the standard scripts
-  are its copies. pixa's own entries follow the standard part: `/bin`, `/data`
-  and the local config files in `.dockerignore`; Go's `*.log`, `*.out` and
-  `*.test`, `vendor/`, the binaries, `/data/`, `*.sqlite3` and the local config
-  files in `.gitignore`. The workflow keeps its `script/docker-smoke` step while
-  https://git.eeqj.de/sneak/pixa/issues/203 is open. The scripts pass a new
-  `CACHEBUST` build argument in place of `--no-cache`, and every `Dockerfile`
-  stage declares it first, so every `RUN` step still runs on every build while
-  Go's build cache, mounted on the steps that compile, is kept; both `go test`
-  runs keep `-count=1`. The lint and test builds write no image. The lint phase
-  runs golangci-lint v2.14.0, the test phase runs on the Debian Go image, and
-  the build stage marks `/src` safe for git. `script/bootstrap`, `script/fmt`
-  and `script/fmt-check` use the node on the `PATH` only when it has the pinned
-  major version. Of golangci-lint v2.14.0's two findings, an unused `nolint`
-  directive is removed, and gosec's new path check is marked as not applying to
-  the fixed config file locations. The agent guidance moves unchanged from
-  `CLAUDE.md` to a root `AGENTS.md`, where `REPO_POLICIES.md` keeps it.
+- 2026-10-15 a WebP, AVIF or JPEG XL encode at the limits takes at most about 27
+  seconds (closes #272): with one libvips thread, 8192x8192 random pixels with
+  an alpha channel took about 61 seconds to encode as WebP, 99 as AVIF and 81 as
+  JPEG XL, so with the default `downstream_timeout` of 60 seconds such an image
+  was never delivered, yet its encode held a processing slot to the end. WebP is
+  now saved at effort 2 and JPEG XL at effort 4, which take up to about 23 and
+  27 seconds. AVIF was already at the lowest effort govips can set, so an AVIF
+  output of more than 16,777,216 pixels is refused with 400 before anything is
+  decoded; 4096x4096 or 8192x2048 takes up to about 25 seconds. Resizing with
+  `fit=cover` already decodes the input, so the output's dimensions are worked
+  out before resizing. `README.md` gives the limit and the new times.
 - 2026-10-15 the request metrics record any method that is not a standard one as
  `other` (closes #274): their `method` label was each request's method as sent,
  and Go's HTTP server accepts any method name, so a client sending made-up
@@ -91,13 +72,13 @@ P2: security: per-origin rate limiting
  each transformed image's `.meta` file, are synced to disk before they are
  renamed into place, and their directory after; the `.meta` file is written
  before the image, and a failed directory sync removes the renamed file. The
-  reconciliation pass, at startup and once a day, removes a cached source or
-  transformed image whose file is empty, or not the size the database records
-  for it, with its rows and a warning naming the file, so the next request
-  fetches the source or converts the image again; requests compare no sizes.
-  Storing a source over a file of another size replaces that file. A source that
-  fails to decode is not removed for that alone: a damaged upstream image would
-  then be fetched on every request.
+  reconciliation pass, at startup and every five minutes, removes a cached
+  source or transformed image whose file is empty, or not the size the database
+  records for it, with its rows and a warning naming the file, so the next
+  request fetches the source or converts the image again; requests compare no
+  sizes. Storing a source over a file of another size replaces that file. A
+  source that fails to decode is not removed for that alone: a damaged upstream
+  image would then be fetched on every request.
 - 2026-10-15 a transcode stops once its request's `downstream_timeout` has
  ended, unless it has begun encoding (closes #243): the image processor looked
  at its context only while it waited for a processing slot, so an image was
@@ -823,7 +823,6 @@ func loadConfigFile(log *slog.Logger, appName string) (*smartconfig.Config, erro
 		// one whose path runs through a file, such as under a HOME of
 		// /dev/null. One that cannot be read or does not parse is a
 		// fatal startup error.
-		//nolint:gosec // G703: a fixed config location; HOME is the operator's
 		_, statErr := os.Stat(cleanPath)
 		if errors.Is(statErr, fs.ErrNotExist) || errors.Is(statErr, syscall.ENOTDIR) {
 			continue
@@ -0,0 +1,49 @@
+package handlers
+
+import (
+	"fmt"
+	"log/slog"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"sneak.berlin/go/pixa/internal/imageprocessor"
+	"sneak.berlin/go/pixa/internal/imgcache"
+)
+
+// TestAVIFOutputTooLargeAnswers400 checks that respondImageError and
+// handleImageError, which answer the errors of the two image routes, answer
+// 400 naming the AVIF pixel limit when the image processor refuses an AVIF
+// output above it, wrapped as the service wraps it. The request's source only
+// goes into a log line, so it is left empty.
+func TestAVIFOutputTooLargeAnswers400(t *testing.T) {
+	t.Parallel()
+
+	h := &Handlers{log: slog.New(slog.DiscardHandler)}
+	err := fmt.Errorf("image processing failed: %w: 4097x4096",
+		imageprocessor.ErrAVIFOutputTooLarge)
+	wantBody := fmt.Sprintf("above %d pixels", imageprocessor.MaxAVIFOutputPixels)
+
+	plain := httptest.NewRecorder()
+	h.respondImageError(plain, &imgcache.ImageRequest{}, err)
+
+	encrypted := httptest.NewRecorder()
+	h.handleImageError(encrypted, err)
+
+	for name, rec := range map[string]*httptest.ResponseRecorder{
+		"respondImageError": plain, "handleImageError": encrypted,
+	} {
+		t.Logf("%s: status = %d, body = %q", name, rec.Code, rec.Body.String())
+
+		if rec.Code != http.StatusBadRequest {
+			t.Errorf("%s: status = %d, want %d",
+				name, rec.Code, http.StatusBadRequest)
+		}
+
+		if !strings.Contains(rec.Body.String(), wantBody) {
+			t.Errorf("%s: body = %q, want it to say %q",
+				name, rec.Body.String(), wantBody)
+		}
+	}
+}
@@ -264,6 +264,14 @@ func (s *Handlers) respondImageError(
 		return
 	}

+	if errors.Is(err, imageprocessor.ErrAVIFOutputTooLarge) {
+		s.respondError(w, fmt.Sprintf("size too large for AVIF: the output "+
+			"would be above %d pixels", imageprocessor.MaxAVIFOutputPixels),
+			http.StatusBadRequest)
+
+		return
+	}
+
 	s.respondError(w, "internal error", http.StatusInternalServerError)
 }

@@ -170,6 +170,10 @@ func (s *Handlers) handleImageError(w http.ResponseWriter, err error) {
 		s.respondError(w, fmt.Sprintf("size too large for the source: the side "+
 			"computed from its proportions is above %d",
 			imageprocessor.MaxOutputDimension), http.StatusBadRequest)
+	case errors.Is(err, imageprocessor.ErrAVIFOutputTooLarge):
+		s.respondError(w, fmt.Sprintf("size too large for AVIF: the output "+
+			"would be above %d pixels", imageprocessor.MaxAVIFOutputPixels),
+			http.StatusBadRequest)
 	default:
 		s.log.Error("image request failed", "error", err)
 		s.respondError(w, "internal error", http.StatusInternalServerError)
@@ -0,0 +1,64 @@
+package imageprocessor
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+)
+
+// TestImageProcessor_RefusesAVIFAboveMaxPixels verifies that an AVIF output
+// of more than MaxAVIFOutputPixels is refused with ErrAVIFOutputTooLarge
+// before anything is decoded, whatever size and fit give it, and that an AVIF
+// output of at most that many pixels, or one in another format, is not. The
+// input is a 64x32 PNG cut off in its pixel data: libvips reads its size from
+// its header but fails when it decodes it, so a request that gets that failure
+// was not refused, and a refusal came before any decoding.
+func TestImageProcessor_RefusesAVIFAboveMaxPixels(t *testing.T) {
+	t.Parallel()
+
+	whole := createTestPNG(t, 64, 32)
+	cutOff := whole[:len(whole)/2]
+
+	tests := []struct {
+		name          string
+		format        Format
+		width, height int
+		fit           FitMode
+		refused       bool
+	}{
+		{"AVIF at the limit", FormatAVIF, 4096, 4096, FitCover, false},
+		{"AVIF above the limit", FormatAVIF, 4096, 4097, FitCover, true},
+		{"WebP above the AVIF limit", FormatWebP, 4096, 4097, FitCover, false},
+		// FitInside does not enlarge, so the output stays 64x32
+		{"AVIF inside a larger size", FormatAVIF, 8192, 8192, FitInside, false},
+		// FitOutside scales 64x32 by 128 to cover 8192x1: 8192x4096
+		{"AVIF outside a smaller size", FormatAVIF, 8192, 1, FitOutside, true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			_, err := New(Params{}).Process(t.Context(), bytes.NewReader(cutOff),
+				&Request{
+					Size:    Size{Width: tt.width, Height: tt.height},
+					Format:  tt.format,
+					FitMode: tt.fit,
+				})
+			t.Logf("Process() error = %v", err)
+
+			if tt.refused {
+				if !errors.Is(err, ErrAVIFOutputTooLarge) {
+					t.Errorf("Process() error = %v, want %v", err, ErrAVIFOutputTooLarge)
+				}
+
+				return
+			}
+
+			if err == nil || errors.Is(err, ErrAVIFOutputTooLarge) {
+				t.Errorf("Process() error = %v, want the failure to decode "+
+					"the cut-off input", err)
+			}
+		})
+	}
+}
@@ -77,10 +77,10 @@ func TestImageProcessor_PNGIsCompressed(t *testing.T) {
 	}
 }

-// TestImageProcessor_WebPAtDefaultEffort verifies that WebP is saved at
-// libvips' default effort, 4: the output is the size of the same image saved
-// at that effort.
-func TestImageProcessor_WebPAtDefaultEffort(t *testing.T) {
+// TestImageProcessor_WebPAtEffort2 verifies that WebP is saved at effort 2,
+// not libvips' default of 4: the output is the size of the same image saved
+// at effort 2.
+func TestImageProcessor_WebPAtEffort2(t *testing.T) {
 	t.Parallel()

 	input := createTestJPEG(t, 200, 150)
@@ -90,14 +90,14 @@ func TestImageProcessor_WebPAtDefaultEffort(t *testing.T) {
 	want, _, err := decode(t, input).ExportWebp(&vips.WebpExportParams{
 		StripMetadata:   true,
 		Quality:         85,
-		ReductionEffort: 4,
+		ReductionEffort: 2,
 	})
 	if err != nil {
 		t.Fatalf("ExportWebp() error = %v", err)
 	}

 	if size != int64(len(want)) {
-		t.Errorf("WebP output is %d bytes, want %d, the size at effort 4",
+		t.Errorf("WebP output is %d bytes, want %d, the size at effort 2",
 			size, len(want))
 	}
 }
@@ -143,3 +143,29 @@ func TestImageProcessor_AVIFAtEffort1(t *testing.T) {
 			"and 8 bits", size, len(want))
 	}
 }
+
+// TestImageProcessor_JPEGXLAtEffort4 verifies that JPEG XL is saved at
+// effort 4, not libvips' default of 7: the output is the size of the same
+// image saved at effort 4, with the distance exportJXL gives quality 85.
+func TestImageProcessor_JPEGXLAtEffort4(t *testing.T) {
+	t.Parallel()
+
+	input := createTestJPEG(t, 200, 150)
+
+	size := processedSize(t, input, &Request{Format: FormatJXL, Quality: 85})
+
+	params := vips.NewJxlExportParams()
+	params.Quality = 85
+	params.Distance = jxlDistance(85)
+	params.Effort = 4
+
+	want, _, err := decode(t, input).ExportJxl(params)
+	if err != nil {
+		t.Fatalf("ExportJxl() error = %v", err)
+	}
+
+	if size != int64(len(want)) {
+		t.Errorf("JPEG XL output is %d bytes, want %d, the size at effort 4",
+			size, len(want))
+	}
+}
@@ -143,6 +143,18 @@ const MaxOutputDimension = 8192
 // requested size.
 var ErrOutputTooLarge = errors.New("output image dimensions exceed maximum")

+// MaxAVIFOutputPixels is the most pixels an AVIF output may have, so that an
+// encode takes at most 40 seconds of the default downstream_timeout of 60
+// seconds; AVIF is already at the lowest effort govips can set (avifEffort).
+// With one thread, as pixad runs libvips, saving 4096x4096 or 8192x2048
+// random pixels with an alpha channel takes up to about 25 seconds, and
+// 5120x4096 took 39.
+const MaxAVIFOutputPixels = 4096 * 4096
+
+// ErrAVIFOutputTooLarge is returned, before anything is decoded, when an AVIF
+// output would have more than MaxAVIFOutputPixels pixels.
+var ErrAVIFOutputTooLarge = errors.New("AVIF output has too many pixels")
+
 // ErrUnsupportedOutputFormat is returned when the requested output format is
 // not supported.
 var ErrUnsupportedOutputFormat = errors.New("unsupported output format")
@@ -211,7 +223,8 @@ func New(params Params) *ImageProcessor {
 // ErrTooManyImages. When ctx has ended once Process has a slot, or before it
 // encodes, it returns ctx's error and gives the slot back. govips gives pixa
 // no way to stop libvips once an encode has begun, so an encode keeps its
-// slot until it finishes.
+// slot until it finishes. An AVIF output of more than MaxAVIFOutputPixels is
+// refused with ErrAVIFOutputTooLarge before anything is decoded.
 func (p *ImageProcessor) Process(
 	ctx context.Context,
 	input io.Reader,
@@ -224,18 +237,9 @@ func (p *ImageProcessor) Process(

 	defer release()

-	// Read input with a size limit to prevent unbounded memory consumption.
-	// We read at most maxInputBytes+1 so we can detect if the input exceeds
-	// the limit without consuming additional memory.
-	limited := io.LimitReader(input, p.maxInputBytes+1)
-
-	data, err := io.ReadAll(limited)
+	data, err := p.readInput(input)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read input: %w", err)
-	}
-
-	if int64(len(data)) > p.maxInputBytes {
-		return nil, ErrInputDataTooLarge
+		return nil, err
 	}

 	// govips picks the libvips loader from the input's first bytes with
@@ -278,20 +282,28 @@ func (p *ImageProcessor) Process(
 		return nil, err
 	}

-	// Resize if needed
-	if targetWidth != origWidth || targetHeight != origHeight {
-		err := p.resize(img, targetWidth, targetHeight, req.FitMode)
-		if err != nil {
-			return nil, fmt.Errorf("failed to resize: %w", err)
-		}
-	}
-
 	// orig is the source's own format; encode refuses an empty format
 	outputFormat := req.Format
 	if outputFormat == FormatOriginal {
 		outputFormat = sourceFormat
 	}

+	// Determine output dimensions; too large ones are refused before
+	// resizing, which with FitCover already decodes the input
+	outputWidth, outputHeight, err := outputDimensions(origWidth, origHeight,
+		targetWidth, targetHeight, req.FitMode, outputFormat)
+	if err != nil {
+		return nil, err
+	}
+
+	// Resize if needed
+	if targetWidth != origWidth || targetHeight != origHeight {
+		err := p.resize(img, outputWidth, outputHeight, req.FitMode)
+		if err != nil {
+			return nil, fmt.Errorf("failed to resize: %w", err)
+		}
+	}
+
 	// Encode to target format
 	output, err := p.encode(ctx, img, outputFormat, req.Quality)
 	if err != nil {
@@ -444,6 +456,23 @@ func (p *ImageProcessor) acquireSlot(ctx context.Context) (func(), error) {
 	return release, nil
 }

+// readInput reads input with a size limit to prevent unbounded memory
+// consumption, refusing more than maxInputBytes with ErrInputDataTooLarge. It
+// reads at most maxInputBytes+1 so it can detect if the input exceeds the
+// limit without consuming additional memory.
+func (p *ImageProcessor) readInput(input io.Reader) ([]byte, error) {
+	data, err := io.ReadAll(io.LimitReader(input, p.maxInputBytes+1))
+	if err != nil {
+		return nil, fmt.Errorf("failed to read input: %w", err)
+	}
+
+	if int64(len(data)) > p.maxInputBytes {
+		return nil, ErrInputDataTooLarge
+	}
+
+	return data, nil
+}
+
 // detectFormat returns the format string for a govips image type.
 func (p *ImageProcessor) detectFormat(imageType vips.ImageType) string {
 	switch imageType {
@@ -468,9 +497,61 @@ func (p *ImageProcessor) detectFormat(imageType vips.ImageType) string {
 	}
 }

-// resize resizes the image according to the fit mode. With FitOutside one
-// side can come out larger than requested; when it would be above
-// MaxOutputDimension, resize returns ErrOutputTooLarge without resizing.
+// outputDimensions returns the dimensions resize gives an image of imgWidth x
+// imgHeight for the target dimensions and fit mode, without resizing it, and
+// refuses an output too large for format. With FitOutside one side can come
+// out larger than the target; when it would be above MaxOutputDimension,
+// outputDimensions returns ErrOutputTooLarge. An AVIF output of more than
+// MaxAVIFOutputPixels is ErrAVIFOutputTooLarge.
+func outputDimensions(
+	imgWidth, imgHeight, width, height int, fit FitMode, format Format,
+) (int, int, error) {
+	scaleW := float64(width) / float64(imgWidth)
+	scaleH := float64(height) / float64(imgHeight)
+	outputWidth, outputHeight := width, height
+
+	switch fit {
+	case FitCover, FitFill, "":
+		// Cover crops, and fill stretches, to exactly the target dimensions
+
+	case FitContain:
+		// Fit within the target dimensions, maintaining aspect ratio
+		scale := min(scaleW, scaleH)
+		outputWidth = int(float64(imgWidth) * scale)
+		outputHeight = int(float64(imgHeight) * scale)
+
+	case FitInside:
+		// Same as contain, but only shrink
+		scale := min(scaleW, scaleH, 1)
+		outputWidth = int(float64(imgWidth) * scale)
+		outputHeight = int(float64(imgHeight) * scale)
+
+	case FitOutside:
+		// The smallest dimension fits, the other may exceed the target
+		scale := max(scaleW, scaleH)
+		outputWidth = int(float64(imgWidth) * scale)
+		outputHeight = int(float64(imgHeight) * scale)
+
+	default:
+		return 0, 0, fmt.Errorf("%w: %s", ErrInvalidFitMode, fit)
+	}
+
+	// The side FitOutside scales past the target is held to the maximum too
+	if max(outputWidth, outputHeight) > MaxOutputDimension {
+		return 0, 0, fmt.Errorf("%w: %dx%d is above %d", ErrOutputTooLarge,
+			outputWidth, outputHeight, MaxOutputDimension)
+	}
+
+	if format == FormatAVIF && outputWidth*outputHeight > MaxAVIFOutputPixels {
+		return 0, 0, fmt.Errorf("%w: %dx%d is above %d pixels",
+			ErrAVIFOutputTooLarge, outputWidth, outputHeight, MaxAVIFOutputPixels)
+	}
+
+	return outputWidth, outputHeight, nil
+}
+
+// resize resizes the image to width x height, the dimensions
+// outputDimensions gives for the fit mode.
 func (p *ImageProcessor) resize(
 	img *vips.ImageRef, width, height int, fit FitMode,
 ) error {
@@ -479,52 +560,20 @@ func (p *ImageProcessor) resize(
 		// Resize and crop to fill exact dimensions (default)
 		return img.Thumbnail(width, height, vips.InterestingCentre)

-	case FitContain:
-		// Resize to fit within dimensions, maintaining aspect ratio
-		imgW, imgH := img.Width(), img.Height()
-		scaleW := float64(width) / float64(imgW)
-		scaleH := float64(height) / float64(imgH)
-		scale := min(scaleW, scaleH)
-		newW := int(float64(imgW) * scale)
-		newH := int(float64(imgH) * scale)
-
-		return img.Thumbnail(newW, newH, vips.InterestingNone)
-
 	case FitFill:
 		// Resize to exact dimensions (may distort)
 		return img.ThumbnailWithSize(width, height, vips.InterestingNone, vips.SizeForce)

 	case FitInside:
-		// Same as contain, but only shrink
-		if img.Width() <= width && img.Height() <= height {
-			return nil // Already fits
+		// outputDimensions keeps the dimensions of an image that already fits
+		if img.Width() == width && img.Height() == height {
+			return nil
 		}

-		imgW, imgH := img.Width(), img.Height()
-		scaleW := float64(width) / float64(imgW)
-		scaleH := float64(height) / float64(imgH)
-		scale := min(scaleW, scaleH)
-		newW := int(float64(imgW) * scale)
-		newH := int(float64(imgH) * scale)
+		return img.Thumbnail(width, height, vips.InterestingNone)

-		return img.Thumbnail(newW, newH, vips.InterestingNone)
-
-	case FitOutside:
-		// Resize so smallest dimension fits, may exceed target on other dimension
-		imgW, imgH := img.Width(), img.Height()
-		scaleW := float64(width) / float64(imgW)
-		scaleH := float64(height) / float64(imgH)
-		scale := max(scaleW, scaleH)
-		newW := int(float64(imgW) * scale)
-		newH := int(float64(imgH) * scale)
-
-		// The dimension that exceeds the target is held to the maximum too
-		if newW > MaxOutputDimension || newH > MaxOutputDimension {
-			return fmt.Errorf("%w: %dx%d is above %d", ErrOutputTooLarge,
-				newW, newH, MaxOutputDimension)
-		}
-
-		return img.Thumbnail(newW, newH, vips.InterestingNone)
+	case FitContain, FitOutside:
+		return img.Thumbnail(width, height, vips.InterestingNone)

 	default:
 		return fmt.Errorf("%w: %s", ErrInvalidFitMode, fit)
@@ -628,11 +677,16 @@ func exportGIF(img *vips.ImageRef) ([]byte, error) {
 	return output, err
 }

-// webpEffort is libvips' default WebP effort, from 0 (fastest) to 6.
-const webpEffort = 4
+// webpEffort is the WebP effort, from 0 (fastest) to 6. It is below libvips'
+// default of 4 so that an encode takes at most 40 seconds of the default
+// downstream_timeout of 60 seconds. With one thread, as pixad runs libvips,
+// saving an 8192x8192 image of random pixels with an alpha channel takes up
+// to about 23 seconds at 2, and up to about 16 without one; with an alpha
+// channel, 3 takes about 50 seconds and 4 about 61.
+const webpEffort = 2

-// exportWebP encodes img as lossy WebP at quality and libvips' default
-// effort, without metadata.
+// exportWebP encodes img as lossy WebP at quality and webpEffort, without
+// metadata.
 func exportWebP(img *vips.ImageRef, quality int) ([]byte, error) {
 	output, _, err := img.ExportWebp(&vips.WebpExportParams{
 		StripMetadata:   true,
@@ -644,12 +698,12 @@ func exportWebP(img *vips.ImageRef, quality int) ([]byte, error) {
 }

 // avifEffort is the AVIF effort, from 0 (fastest) to 9; 1 is the lowest
-// govips can set. With one thread, as pixad runs libvips, 1 takes about 51
-// seconds to save an 8192x8192 RGB image of random pixels, and about 110
-// with an alpha channel, the worst case, against the default
-// downstream_timeout of 60 seconds. On an image of milder noise, which 1
-// saves in about 12 seconds, 2 takes nearly a minute and libvips' default,
-// 4, takes minutes.
+// govips can set. With one thread, as pixad runs libvips, 1 takes about 58
+// seconds to save an 8192x8192 RGB image of random pixels, and about 99
+// with an alpha channel, against the default downstream_timeout of 60
+// seconds, so an AVIF output is held to MaxAVIFOutputPixels. On an image of
+// milder noise, which 1 saves in about 12 seconds, 2 takes nearly a minute
+// and libvips' default, 4, takes minutes.
 const avifEffort = 1

 // avifBitdepth is the AVIF bit depth, 8 bits per sample for every image.
@@ -676,10 +730,18 @@ func exportAVIF(img *vips.ImageRef, quality int) ([]byte, error) {
 // JPEG that names none.
 const jxlResolution = 72 / 25.4

-// exportJXL encodes img as JPEG XL at quality, with libvips' default effort
-// and without metadata. govips sends libvips a distance, the JPEG XL
-// encoder's own measure of quality, along with the quality, and libvips then
-// uses the distance alone, so the quality is also given as a distance.
+// jxlEffort is the JPEG XL effort, from 1 (fastest) to 9. It is below
+// libvips' default of 7 so that an encode takes at most 40 seconds of the
+// default downstream_timeout of 60 seconds. With one thread, as pixad runs
+// libvips, saving an 8192x8192 image of random pixels with an alpha channel
+// takes up to about 27 seconds at 4, and up to about 13 without one; with an
+// alpha channel, 5 takes about 43 seconds and 7 about 81.
+const jxlEffort = 4
+
+// exportJXL encodes img as JPEG XL at quality and jxlEffort, without
+// metadata. govips sends libvips a distance, the JPEG XL encoder's own
+// measure of quality, along with the quality, and libvips then uses the
+// distance alone, so the quality is also given as a distance.
 func exportJXL(img *vips.ImageRef, quality int) ([]byte, error) {
 	// libvips converts a CMYK image to sRGB before it saves WebP, AVIF or
 	// PNG, but cannot save one as JPEG XL. encode has already converted
@@ -718,6 +780,7 @@ func exportJXL(img *vips.ImageRef, quality int) ([]byte, error) {
 	params := vips.NewJxlExportParams()
 	params.Quality = quality
 	params.Distance = jxlDistance(quality)
+	params.Effort = jxlEffort

 	output, _, err := toSave.ExportJxl(params)
 	if err != nil {
@@ -78,6 +78,10 @@ func (c *Cache) computeDefaultMaxBytes(
 	computed := spaceBytes / freeSpaceFractionDenominator * freeSpaceFractionNumerator
 	computed = min(computed, math.MaxInt64)

+	// gosec cannot see that min() above bounds computed, so it reads
+	// this conversion as potentially overflowing. It cannot: computed is
+	// at most math.MaxInt64 on every path here.
+	//nolint:gosec // G115: clamped to MaxInt64 by min above
 	limit := int64(computed)
 	limit = max(limit, DefaultCacheMaxBytesFloor)

@@ -18,11 +18,6 @@ import (
 // write-pressure wakeups triggered by stores.
 const DefaultEvictionInterval = 5 * time.Minute

-// reconciliationInterval is how long after one reconciliation pass ends
-// the next one starts. A pass reads a row for every cached file, so its
-// cost grows with the cache, and it runs this rarely for that reason.
-const reconciliationInterval = 24 * time.Hour
-
 // evictionBatchSize is how many LRU candidates of each class (variants
 // and source blobs) one eviction pass fetches from the database.
 const evictionBatchSize = 100
@@ -442,17 +437,15 @@ func (c *Cache) notifyWritePressure() {
 	}
 }

-// StartEviction launches the background eviction goroutine. At startup
-// it reconciles the database accounting with the cache directories,
-// removes the expired negative cache rows and evicts to the configured
-// limit. After that it reconciles again a day after each reconciliation
-// pass ends, removes the expired negative cache rows on every tick of
-// the given interval, and evicts to the limit on every tick, after each
-// reconciliation pass and on write-pressure notifications. On a disabled
-// cache it only removes the expired negative cache rows, as the negative
-// cache is used either way. It is a no-op when already started. The
-// goroutine outlives the caller, so it runs with its own context, which
-// StopEviction cancels.
+// StartEviction launches the background eviction goroutine, which
+// reconciles the database accounting with the cache directories and
+// removes the expired negative cache rows at startup and again on every
+// periodic tick thereafter, and evicts to the configured limit on the
+// given periodic interval and on write-pressure notifications. On a
+// disabled cache it only removes the expired negative cache rows, as
+// the negative cache is used either way. It is a no-op when already
+// started. The goroutine outlives the caller, so it runs with its own
+// context, which StopEviction cancels.
 func (c *Cache) StartEviction(interval time.Duration) {
 	if c.evictionCancel != nil {
 		return
@@ -493,16 +486,6 @@ func (c *Cache) evictionLoop(ctx context.Context, interval time.Duration) {
 	c.runCleanExpired(ctx)
 	c.runEvictionPass(ctx)

-	// Reconciliation walks the cache directories and reads a row for
-	// every file, so it runs on a timer of its own rather than on the
-	// periodic tick or on write-pressure wakeups. The timer starts only
-	// once a pass has ended, so passes never run back to back, however
-	// long one takes. Running it daily, not just at startup, bounds how
-	// long a store's best-effort accounting insert can stay silently
-	// unaccounted for to about one day, plus the time the passes take.
-	reconciliationTimer := time.NewTimer(reconciliationInterval)
-	defer reconciliationTimer.Stop()
-
 	ticker := time.NewTicker(interval)
 	defer ticker.Stop()

@@ -510,10 +493,17 @@ func (c *Cache) evictionLoop(ctx context.Context, interval time.Duration) {
 		select {
 		case <-ctx.Done():
 			return
-		case <-reconciliationTimer.C:
-			c.runReconciliationPass(ctx)
-			reconciliationTimer.Reset(reconciliationInterval)
 		case <-ticker.C:
+			// Reconciliation walks the cache directories, so it only
+			// runs on the periodic ticker rather than on every
+			// write-pressure wakeup, keeping it off the per-store hot
+			// path. Reusing the eviction interval itself (rather than a
+			// separate, longer one) is a deliberate choice: it is the
+			// simplest option that still bounds how long a store's
+			// best-effort accounting insert can stay silently
+			// unaccounted for to one interval, on a process that is
+			// already running this loop regardless.
+			c.runReconciliationPass(ctx)
 			c.runCleanExpired(ctx)
 		case <-c.evictionPressure:
 		}
@@ -566,18 +556,19 @@ func (c *Cache) runCleanExpired(ctx context.Context) {

 // reconcileAccounting synchronizes the database size accounting with
 // the actual contents of the cache directories. It runs at startup and
-// then once a day, off the request hot path: it adopts variant files
-// that predate the accounting table (or whose accounting insert failed,
-// e.g. StoreVariant's best-effort insert under transient DB contention),
-// drops accounting rows whose files are missing, removes source blob
-// files the database does not know (and rows whose files are gone),
-// removes source and variant files that are empty or not the size their
-// rows record, sweeps stale temp files left behind by crashed writes,
-// and last checks the total cache usage against the tables. It reads the
-// tables a page at a time. Running it daily, not just once, bounds how
-// long such drift can accumulate unaccounted for on a long-running
-// process to about one day. Once ctx is cancelled, it stops at the next
-// file or row and returns ctx's error.
+// again on every periodic eviction tick thereafter, off the request
+// hot path: it adopts variant files that predate the accounting table
+// (or whose accounting insert failed, e.g. StoreVariant's best-effort
+// insert under transient DB contention), drops accounting rows whose
+// files are missing, removes source blob files the database does not
+// know (and rows whose files are gone), removes source and variant files
+// that are empty or not the size their rows record, sweeps stale temp
+// files left behind by crashed writes, and last checks the total cache
+// usage against the tables. It reads the tables a page at a time.
+// Running it periodically, not just once, bounds how long such drift can
+// accumulate unaccounted for on a long-running process to one eviction
+// interval. Once ctx is cancelled, it stops at the next file or row and
+// returns ctx's error.
 func (c *Cache) reconcileAccounting(ctx context.Context) error {
 	if c.disabled {
 		return nil
@@ -9,9 +9,7 @@ import (
 	"log/slog"
 	"os"
 	"path/filepath"
-	"strconv"
 	"strings"
-	"sync/atomic"
 	"testing"
 	"time"

@@ -920,84 +918,6 @@ func TestPeriodicReconciliationAdoptsFileThatAppearsAfterStartup(t *testing.T) {
 	}
 }

-// TestEvictionTicksDoNotReconcile starts the eviction loop with an
-// interval of 10 ms. The startup pass reconciles before it removes the
-// expired negative cache rows, so once the expired row stored before the
-// start is gone, the startup reconciliation has made all its reads. The
-// test then waits for three periodic ticks, each seen when it removes an
-// expired row stored after the previous one went. The reconciliation
-// pass runs at startup and then once a day, so none of those ticks may
-// read a content table for reconciliation.
-func TestEvictionTicksDoNotReconcile(t *testing.T) {
-	t.Parallel()
-
-	cache, _ := newEvictionTestCache(t, 1<<30)
-
-	var reconciliationReads atomic.Int64
-
-	cache.reconciliationReadTestHook = func(int) { reconciliationReads.Add(1) }
-
-	insertExpiredNegativeCacheRow(t, cache, "/startup.jpg")
-
-	cache.StartEviction(10 * time.Millisecond)
-	defer func() { _ = cache.StopEviction(t.Context()) }()
-
-	waitForNegativeCacheRowRemoved(t, cache, "/startup.jpg")
-
-	startupReads := reconciliationReads.Load()
-	t.Logf("the startup pass made %d reconciliation reads", startupReads)
-
-	if startupReads == 0 {
-		t.Fatal("the startup pass made no reconciliation read")
-	}
-
-	for tick := range 3 {
-		path := "/tick-" + strconv.Itoa(tick) + ".jpg"
-
-		insertExpiredNegativeCacheRow(t, cache, path)
-		waitForNegativeCacheRowRemoved(t, cache, path)
-	}
-
-	tickReads := reconciliationReads.Load() - startupReads
-	t.Logf("three eviction ticks made %d reconciliation reads", tickReads)
-
-	if tickReads != 0 {
-		t.Errorf("three eviction ticks made %d reconciliation reads, want 0: "+
-			"the reconciliation pass ran on an eviction tick", tickReads)
-	}
-}
-
-// insertExpiredNegativeCacheRow adds a negative_cache row for sourcePath
-// that expired an hour ago.
-func insertExpiredNegativeCacheRow(t *testing.T, cache *Cache, sourcePath string) {
-	t.Helper()
-
-	_, err := cache.db.ExecContext(t.Context(), `
-		INSERT INTO negative_cache
-			(source_host, source_path, status_code, expires_at)
-		VALUES (?, ?, 404, datetime('now', '-1 hour'))
-	`, testHostExample, sourcePath)
-	if err != nil {
-		t.Fatalf("failed to insert an expired negative cache row: %v", err)
-	}
-}
-
-// waitForNegativeCacheRowRemoved waits up to five seconds for the
-// eviction loop to remove the negative_cache row for sourcePath.
-func waitForNegativeCacheRowRemoved(t *testing.T, cache *Cache, sourcePath string) {
-	t.Helper()
-
-	deadline := time.Now().Add(5 * time.Second)
-
-	for negativeCacheRowCount(t, cache, sourcePath) > 0 {
-		if time.Now().After(deadline) {
-			t.Fatalf("the expired negative cache row for %s was not removed", sourcePath)
-		}
-
-		time.Sleep(10 * time.Millisecond)
-	}
-}
-
 // TestStopEvictionInterruptsPassInProgress holds the test database's
 // only connection, so the startup reconciliation pass waits for it, and
 // checks that StopEviction stops that pass instead of waiting for the
@@ -3,13 +3,11 @@
 # this repo. Idempotent: every install is guarded by a check so already
 # installed tools are skipped. Base tooling comes from nix, apt, brew,
 # or apk (detected in that order); assumes NOTHING is present (not git,
-# make, or go). The installed node is used only when its major version
-# is the pinned one; otherwise (node missing, or another major) the
-# pinned version is installed via nvm (installing nvm itself first,
-# from a hash-verified release archive, never curl | sh), and yarn and
-# the packages are installed under it. The linter is never installed on
-# the host: golangci-lint runs only in the lint phase of the Dockerfile
-# (see script/lint).
+# make, or go). Node is used directly if installed; otherwise it is
+# installed at a pinned version via nvm (installing nvm itself first,
+# from a hash-verified release archive, never curl | sh). The linter is
+# never installed on the host: golangci-lint runs only in the lint phase
+# of the Dockerfile (see script/lint).
 #
 #   script/bootstrap         git, make, Go, and Node, Yarn and the
 #                            prettier in yarn.lock for script/fmt and
@@ -112,50 +110,31 @@ ensure_nvm() {
    rm -rf "$tmp"
 }

-# True when the node on PATH has the pinned major version. Only the
-# major is compared, as REPO_POLICIES.md asks. Another major is not
-# used: the pinned yarn 1 prints a deprecation warning under node 24.
-# script/fmt and script/fmt-check carry this function unchanged, to run
-# the yarn installed here.
-node_is_pinned_major() {
-    if ! command -v node >/dev/null 2>&1; then return 1; fi
-    installed="$(node --version)"
-    installed="${installed#v}"
-    [ "${installed%%.*}" = "${NODE_VERSION%%.*}" ]
-}
-
 ensure_node() {
-    if node_is_pinned_major; then
-        echo "bootstrap: using node $(node --version)"
-        return 0
-    fi
+    if ! missing node; then return 0; fi
    ensure_nvm
    nvm_sh "nvm install $NODE_VERSION"
-    nvm_sh "nvm use $NODE_VERSION >/dev/null && \
-        echo \"bootstrap: using node \$(node --version)\""
 }

 ensure_yarn() {
-    if ! node_is_pinned_major; then
-        nvm_sh "nvm use $NODE_VERSION >/dev/null && corepack enable && \
-            corepack prepare yarn@$YARN_VERSION --activate"
-        return 0
-    fi
    if ! missing yarn; then return 0; fi
    if ! missing corepack; then
        corepack enable
        corepack prepare "yarn@$YARN_VERSION" --activate
+    elif [ -s "$HOME/.nvm/nvm.sh" ]; then
+        nvm_sh "nvm use $NODE_VERSION >/dev/null && corepack enable && \
+            corepack prepare yarn@$YARN_VERSION --activate"
    else
        npm install -g "yarn@$YARN_VERSION"
    fi
 }

 install_js_deps() {
-    if node_is_pinned_major; then
-        yarn install --frozen-lockfile
-    else
+    if missing yarn && [ -s "$HOME/.nvm/nvm.sh" ]; then
        nvm_sh "nvm use $NODE_VERSION >/dev/null && cd \"$ROOT\" && \
            yarn install --frozen-lockfile"
+    else
+        yarn install --frozen-lockfile
    fi
 }

@@ -2,11 +2,9 @@
 # script/cibuild: run the CI build. It bootstraps first: a CI runner
 # checks out and runs this and nothing else, and script/fmt-check runs
 # the formatter on the host, which a pristine checkout cannot do.
-# A new CACHEBUST value reruns every RUN step, since a cached gate phase
-# is a check that did not run; unlike --no-cache, it keeps Go's build cache.
-# This relies on every stage of the Dockerfile declaring ARG CACHEBUST
-# first; a stage without that line is served from cache on an unchanged
-# tree, with no warning.
+# --no-cache for the same reason as script/docker: the gate phases the
+# final stage depends on are RUN steps, and a cached one is a check that
+# did not run.
 set -eu

 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -16,17 +14,16 @@ main() {
    cd "$ROOT"
    "$SCRIPT_DIR/bootstrap"
    "$SCRIPT_DIR/check"
-    # The version and the tag each get their own line: a failing
-    # command substitution inside an argument does not trip `set -e`,
-    # so the inline form degrades silently to an empty constant. The
-    # VERSION build argument takes precedence over the version a build
-    # stage derives from the .git in the context.
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. VERSION is computed here because .dockerignore
+    # excludes .git, so `git describe` in a build stage yields an empty
+    # version without failing.
    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
    [ -n "$version" ] || version="unknown"
-    tag="$("$SCRIPT_DIR/projectname")"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
        --build-arg VERSION="$version" \
-        -t "$tag" .
+        -t "$("$SCRIPT_DIR/projectname")" .
 }

 main "$@"
@@ -1,11 +1,8 @@
 #!/bin/sh
 # script/docker: build the Docker image tagged with the project name.
 # Identical in all repos; the tag comes from script/projectname.
-# A new CACHEBUST value reruns every RUN step, since a cached gate phase
-# is a check that did not run; unlike --no-cache, it keeps Go's build cache.
-# This relies on every stage of the Dockerfile declaring ARG CACHEBUST
-# first; a stage without that line is served from cache on an unchanged
-# tree, with no warning.
+# --no-cache because the gate phases the final stage depends on are RUN
+# steps, and a cached one is a check that did not run.
 set -eu

 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -13,17 +10,16 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"

 main() {
    cd "$ROOT"
-    # The version and the tag each get their own line: a failing
-    # command substitution inside an argument does not trip `set -e`,
-    # so the inline form degrades silently to an empty constant. The
-    # VERSION build argument takes precedence over the version a build
-    # stage derives from the .git in the context.
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. VERSION is computed here because .dockerignore
+    # excludes .git, so `git describe` in a build stage yields an empty
+    # version without failing.
    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
    [ -n "$version" ] || version="unknown"
-    tag="$("$SCRIPT_DIR/projectname")"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
        --build-arg VERSION="$version" \
-        -t "$tag" .
+        -t "$("$SCRIPT_DIR/projectname")" .
 }

 main "$@"
@@ -7,25 +7,15 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 # Must match the pin in script/bootstrap.
 NODE_VERSION="22.17.0"

-# True when the node on PATH has the pinned major version: the same
-# function as in script/bootstrap, which uses it to decide where it
-# installs yarn.
-node_is_pinned_major() {
-    if ! command -v node >/dev/null 2>&1; then return 1; fi
-    installed="$(node --version)"
-    installed="${installed#v}"
-    [ "${installed%%.*}" = "${NODE_VERSION%%.*}" ]
-}
-
-# Run the yarn script/bootstrap installed: the yarn on PATH when the
-# node on PATH has the pinned major version, and otherwise yarn under
-# the pinned node in nvm, which bootstrap leaves off the PATH of the
-# shell that called it. nvm is a bash script, hence the subshell.
+# script/bootstrap installs node and yarn under nvm and leaves neither
+# on the PATH of the shell that called it, so resolve the pinned
+# toolchain here the way bootstrap's own install step does. nvm is a
+# bash script, hence the subshell.
 run_yarn() {
-    if node_is_pinned_major && command -v yarn >/dev/null 2>&1; then
+    if command -v yarn >/dev/null 2>&1; then
        exec yarn "$@"
    fi
-    if node_is_pinned_major || [ ! -s "$HOME/.nvm/nvm.sh" ]; then
+    if [ ! -s "$HOME/.nvm/nvm.sh" ]; then
        echo "fmt: no yarn; run script/bootstrap first" >&2
        exit 1
    fi
@@ -8,25 +8,15 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 # Must match the pin in script/bootstrap.
 NODE_VERSION="22.17.0"

-# True when the node on PATH has the pinned major version: the same
-# function as in script/bootstrap, which uses it to decide where it
-# installs yarn.
-node_is_pinned_major() {
-    if ! command -v node >/dev/null 2>&1; then return 1; fi
-    installed="$(node --version)"
-    installed="${installed#v}"
-    [ "${installed%%.*}" = "${NODE_VERSION%%.*}" ]
-}
-
-# Run the yarn script/bootstrap installed: the yarn on PATH when the
-# node on PATH has the pinned major version, and otherwise yarn under
-# the pinned node in nvm, which bootstrap leaves off the PATH of the
-# shell that called it. nvm is a bash script, hence the subshell.
+# script/bootstrap installs node and yarn under nvm and leaves neither
+# on the PATH of the shell that called it, so resolve the pinned
+# toolchain here the way bootstrap's own install step does. nvm is a
+# bash script, hence the subshell.
 run_yarn() {
-    if node_is_pinned_major && command -v yarn >/dev/null 2>&1; then
+    if command -v yarn >/dev/null 2>&1; then
        exec yarn "$@"
    fi
-    if node_is_pinned_major || [ ! -s "$HOME/.nvm/nvm.sh" ]; then
+    if [ ! -s "$HOME/.nvm/nvm.sh" ]; then
        echo "fmt-check: no yarn; run script/bootstrap first" >&2
        exit 1
    fi
@@ -5,12 +5,9 @@
 # make its answer untrustworthy.
 #
 # The phase is not the last stage in the file, so it is built only when
-# --target names it. A new CACHEBUST value reruns every RUN step, since
-# a cached lint layer is a lint that did not run; unlike --no-cache, it
-# keeps Go's build cache. This relies on every stage of the Dockerfile
-# declaring ARG CACHEBUST first; a stage without that line is served
-# from cache on an unchanged tree, with no warning.
-# --output type=cacheonly writes no image, since nothing uses one.
+# --target names it. --no-cache because a cached lint layer is a lint
+# that did not run. The tag makes each build replace the previous image
+# instead of leaving a dangling one behind.
 set -eu

 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -18,9 +15,9 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"

 main() {
    cd "$ROOT"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
        --target lint \
-        --output type=cacheonly .
+        -t "$("$SCRIPT_DIR/projectname")-lint" .
 }

 main "$@"
@@ -2,12 +2,8 @@
 # script/test: run the test suite. Testing is a phase of the Dockerfile
 # and this builds that phase alone, on the same terms as script/lint:
 # --target because a phase that is not the last stage is built only when
-# named, and a new CACHEBUST value because a cached test layer is a test
-# that did not run; unlike --no-cache, it keeps Go's build cache. This
-# relies on every stage of the Dockerfile declaring ARG CACHEBUST first;
-# a stage without that line is served from cache on an unchanged tree,
-# with no warning. --output type=cacheonly writes no image, since
-# nothing uses one.
+# named, --no-cache because a cached test layer is a test that did not
+# run, and a tag so each build replaces the previous image.
 set -eu

 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
@@ -15,9 +11,9 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"

 main() {
    cd "$ROOT"
-    docker build --build-arg CACHEBUST="$(date +%s)-$$" \
+    docker build --no-cache \
        --target test \
-        --output type=cacheonly .
+        -t "$("$SCRIPT_DIR/projectname")-test" .
 }

 main "$@"