Re-vendor the canonical files from sneak/prompts at dd4027b (closes #13)

`.dockerignore`, `.gitignore`, `.golangci.yml` and the workflow are their
copies at that commit. This repo's own entries are kept after the
canonical content: the anchored `/attrsum` binary, the Go entries in
`.gitignore`, and tabs for `*.go` in the new `.editorconfig`.
`REPO_POLICIES.md` is new. The workflow keeps `fetch-depth: 0`, which the
policies require of a repo that stamps a tag-derived version.

The lint phase moves to golangci-lint v2.14.0, which finds nothing in
the code. `script/fmt` now runs goimports with `go run` at its pinned
commit. A version-checked install by `script/bootstrap` would have to be
found on `PATH`, and the CI runner's `PATH` lacks Go's bin directory.

Model: opus-5-5

.dockerignore

@@ -0,0 +1,75 @@
+# .dockerignore does NOT use .gitignore semantics. Docker matches with
+# moby/patternmatcher: filepath.Match plus `**`, so `*` does not cross
+# `/` and an unprefixed pattern is anchored at the context root. Every
+# depth-independent pattern therefore needs `**/`, or `config/.env` and
+# `certs/server.key` still ship while this file reads as solved. Only
+# genuinely root-anchored entries go unprefixed. Never transplant these
+# into .gitignore, where `**/` is wrong.
+#
+# Matching is case-sensitive, so secrets use character ranges rather
+# than an ALL-CAPS twin, which would still miss `Server.Key`.
+#
+# Extend with this repo's own host-built artifacts, written anchored:
+# `/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
+# 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
+
+# Agent scratch: one full checkout of the repo per in-flight agent.
+# Anchored because it occurs once where agents run at the repo root.
+# KNOWN GAP: a repo running agents in subdirectories still ships
+# `services/api/.claude/` and must add its own anchored entry.
+.claude
+
+# Environment files. `*.env` covers bare `.env` and the `prod.env`
+# convention. Re-include a committed template with a negation if the
+# build needs one: `!docs/example.env`.
+**/*.[eE][nN][vV]
+**/.[eE][nN][vV].*
+**/.[eE][nN][vV][rR][cC]
+
+# Private keys and the bundles carrying them. Public certificates
+# (*.crt, *.cer) are deliberately absent: they are legitimate inputs.
+**/*.[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]
+
+# Dependencies: restored inside the image, never copied in.
+**/node_modules
+
+# OS metadata.
+**/.DS_Store
+**/Thumbs.db
+
+# Editor state: never a build input, and it churns COPY.
+**/*.swp
+**/*.swo
+**/*~
+**/*.bak
+**/.idea
+**/.vscode
+**/*.sublime-*
+
+# This repo's host-built binary (`make build`); the image builds its own.
+/attrsum

.editorconfig

@@ -0,0 +1,15 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[Makefile]
+indent_style = tab
+
+[*.go]
+indent_style = tab

.gitea/workflows/check.yml

@@ -4,6 +4,10 @@ jobs:
     check:
         runs-on: ubuntu-latest
         steps:
-            # actions/checkout v4.2.2, 2026-02-28
+            # actions/checkout v4.2.2, 2026-02-22
             - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
+              # Full history and tags, so the build stamps the same
+              # `git describe` version as a full clone.
+              with:
+                  fetch-depth: 0
             - run: script/cibuild

.gitignore

@@ -1 +1,55 @@
-attrsum
+# OS
+.DS_Store
+Thumbs.db
+
+# Editors
+*.swp
+*.swo
+*~
+*.bak
+.idea/
+.vscode/
+*.sublime-*
+
+# Agent scratch (worktrees of this repo, created and destroyed by
+# in-flight tooling). Unanchored: .gitignore patterns already match at
+# every depth, so no prefix is wanted here. This is not a .dockerignore
+# 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 after these lines, 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 repo's own entries, kept after the canonical content above: Go
+# logs, coverage output and test binaries, and the binary `make build`
+# writes.
+*.log
+*.out
+*.test
+/attrsum

.golangci.yml

@@ -1,32 +1,99 @@
 version: "2"
 
+# Config schema uses the golangci-lint v2 layout (settings live under
+# linters.settings, not top-level linters-settings) so that the
+# thresholds below are actually applied by golangci-lint >= v2.
+
 run:
   timeout: 5m
   modules-download-mode: readonly
 
 linters:
   default: all
+  enable:
+    # Successor to the deprecated gomodguard. Named explicitly, rather than
+    # left to `default: all`, because it carries the module policy below.
+    - gomodguard_v2
   disable:
     # Genuinely incompatible with project patterns
     - exhaustruct      # Requires all struct fields
-    - depguard         # Dependency allow/block lists
+    - exhaustruct_v5   # Requires all struct fields (successor to exhaustruct)
     - godot            # Requires comments to end with periods
-    - wsl              # Deprecated, replaced by wsl_v5
     - wrapcheck        # Too verbose for internal packages
     - varnamelen       # Short names like db, id are idiomatic Go
-
+    # Deprecated: the warning is attached to the old name, so it is
-linters-settings:
+    # silenced by disabling that name, not by enabling the successor.
-  lll:
+    - wsl              # Deprecated, replaced by wsl_v5
-    line-length: 88
+    - gomodguard       # Deprecated, replaced by gomodguard_v2
-  funlen:
+  settings:
-    lines: 80
+    lll:
-    statements: 50
+      line-length: 88
-  cyclop:
+    funlen:
-    max-complexity: 15
+      lines: 80
-  dupl:
+      statements: 50
-    threshold: 100
+    cyclop:
+      max-complexity: 15
+    dupl:
+      threshold: 100
+    depguard:
+      # Test-support code must not be compiled into the shipped binary. A
+      # test-support package exists to hand a test privileges the program
+      # itself must never have, so a file that is not a test must not import
+      # one. Test files, and the files inside a package whose directory name
+      # ends in `test`, are where that code belongs, and are exempt.
+      #
+      # The deny list below is the one part of this file a repository is
+      # expected to extend, and the only part it may. depguard matches an
+      # import path against a list of prefixes, so it cannot be told "any path
+      # whose last segment ends in test"; a repository's own test-support
+      # packages have to be named here one at a time, by full import path,
+      # under a module path that differs from repository to repository. Add
+      # them; change nothing else.
+      rules:
+        test-support:
+          list-mode: lax
+          files:
+            - "$all"
+            - "!$test"
+            - "!**/*test/**"
+          deny:
+            - pkg: net/http/httptest
+              desc: >-
+                Test-support code belongs in test files and in packages whose
+                directory name ends in test, not in the shipped binary.
+    # Only decisions already recorded in the Go package defaults are
+    # listed here. Every entry matches the module path exactly.
+    gomodguard_v2:
+      blocked:
+        - module: github.com/rs/zerolog
+          recommendations:
+            - log/slog
+          reason: "Structured logging is stdlib log/slog."
+        # One entry per pre-fork module path, because the later releases
+        # are separate paths. A prefix match would be shorter but would
+        # also reach github.com/go-redis/redismock, the test double for
+        # the successor these entries recommend.
+        - module: github.com/go-redis/redis
+          recommendations:
+            - github.com/redis/go-redis/v9
+          reason: "Pre-fork module; use the maintained go-redis v9."
+        - module: github.com/go-redis/redis/v7
+          recommendations:
+            - github.com/redis/go-redis/v9
+          reason: "Pre-fork module; use the maintained go-redis v9."
+        - module: github.com/go-redis/redis/v8
+          recommendations:
+            - github.com/redis/go-redis/v9
+          reason: "Pre-fork module; use the maintained go-redis v9."
+        - module: github.com/sergi/go-diff
+          recommendations:
+            - github.com/aymanbagabas/go-udiff
+          reason: "No unified diff output; use go-udiff."
+        - module: github.com/hexops/gotextdiff
+          recommendations:
+            - github.com/aymanbagabas/go-udiff
+          reason: "Unmaintained fork; use go-udiff."
 
 issues:
-  exclude-use-default: false
   max-issues-per-linter: 0
   max-same-issues: 0

Dockerfile

@@ -1,35 +1,57 @@
-# Build stage
+# Lint phase
-# golang 1.25-alpine, 2026-02-28
+# golangci/golangci-lint:v2.14.0, 2026-10-06
-FROM golang@sha256:f6751d823c26342f9506c03797d2527668d095b0a15f1862cddb4d927a7a4ced AS builder
+FROM golangci/golangci-lint@sha256:ad862ba6b3798cbe0fd9fd7408d498fd74fbd2623a92406b2fd3898faf0bf98f AS lint
-
-RUN apk add --no-cache git make gcc musl-dev binutils-gold
-
-# golangci-lint v2.10.1
-RUN go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@5d1e709b7be35cb2025444e19de266b056b7b7ee
-# goimports v0.42.0
-RUN go install golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0
-
 WORKDIR /src
 COPY go.mod go.sum ./
 RUN go mod download
+COPY . .
+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. The tests run as an
+# unprivileged user: root can read a file with mode 0000, so the
+# permission tests would fail.
+# golang:1.25.7-trixie, 2026-10-06
+FROM golang@sha256:2b174ffcf56c7ad0c47d30d2630693265639ddf2a5141149c2da34db921791b4 AS test
+RUN useradd --create-home testuser
+USER testuser
+WORKDIR /src
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN go test -timeout 90s -race -cover ./... || \
+    { echo "--- Rerunning with -v for details ---"; \
+      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 1.25-alpine, 2026-02-28
+FROM golang@sha256:f6751d823c26342f9506c03797d2527668d095b0a15f1862cddb4d927a7a4ced AS builder
+COPY --from=lint /src/go.sum /dev/null
+COPY --from=test /src/go.sum /dev/null
+RUN apk add --no-cache git make
+# 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 . .
 
-# Run the checks as an unprivileged user. Root bypasses file mode bits, which
+# The version stamped into the binary: the VERSION build argument when one
-# would make the permission tests (expecting EACCES on a 0000 file) spuriously
+# is given, otherwise `git describe --tags --always` of the .git the build
-# pass with no error. Caches live under /tmp (world-writable) so the user needs
+# context carries: the tag on a tagged commit, tag-N-gHASH on a commit after
-# no home directory of its own.
+# one, the short commit when no tag is reachable. A context that carries .git
-ENV GOCACHE=/tmp/gocache
+# and still yields no version fails the build. With neither, as from a source
-ENV XDG_CACHE_HOME=/tmp/xdgcache
+# tarball, the binary reports dev.
-RUN adduser -D -u 1000 builder && chown -R builder:builder /src /go
+ARG VERSION
-USER builder
+RUN version="${VERSION:-$(git describe --tags --always)}"; \
-
+    if [ -e .git ] && { [ -z "$version" ] || [ "$version" = dev ] || \
-# Run all checks - build fails if any check fails
+        [ "$version" = unknown ]; }; then \
-RUN make check
+        echo "version is '$version' although .git is present" >&2; \
-
+        exit 1; \
-# Build the binary (still as the unprivileged user: it owns /src, so git VCS
+    fi; \
-# stamping sees consistent ownership).
+    make build VERSION="${version:-dev}"
-RUN make build
 
 # Runtime stage
 # alpine 3.21, 2026-02-28

Makefile

@@ -1,6 +1,9 @@
 .PHONY: default bootstrap setup test lint fmt fmt-check check docker hooks build clean try
 
-TESTDIR := $(HOME)/Documents/_SYSADMIN/cyberdyne
+# The version `make build` stamps into the binary: the git tag or short
+# commit, -dirty with uncommitted changes. `make build VERSION=x` stamps x,
+# which is how the Dockerfile passes its version in.
+VERSION ?= $(shell git describe --tags --always --dirty 2>/dev/null || echo dev)
 
 # Standard targets are thin shims; the implementations live in script/
 # per the scripts-to-rule-them-all pattern.
@@ -35,18 +38,27 @@ hooks:
 	@script/install-precommit
 
 build: clean
-	@go build .
+	@go build -ldflags "-X main.Version=$(VERSION)" .
 
 clean:
 	@rm -f attrsum
 
+# Runs the binary on three small files in a new temporary directory, which
+# the trap removes when the recipe ends, also when a step fails. The check
+# after clear is expected to fail, so its exit status is ignored.
 try: build
-	./attrsum sum add -v $(TESTDIR)
+	@set -ex; \
-	./attrsum check -v $(TESTDIR)
+	dir=$$(mktemp -d); \
-	./attrsum clear -v $(TESTDIR)
+	trap 'rm -rf "$$dir"' EXIT; \
-	-./attrsum check -v $(TESTDIR)
+	echo one >"$$dir/a"; \
-	./attrsum sum add -v $(TESTDIR)
+	echo two >"$$dir/b"; \
-	./attrsum check -v $(TESTDIR)
+	echo three >"$$dir/c"; \
-	touch $(TESTDIR)/*
+	./attrsum sum add -v "$$dir"; \
-	./attrsum sum update -v $(TESTDIR)
+	./attrsum check -v "$$dir"; \
-	./attrsum check -v $(TESTDIR)
+	./attrsum clear -v "$$dir"; \
+	./attrsum check -v "$$dir" || true; \
+	./attrsum sum add -v "$$dir"; \
+	./attrsum check -v "$$dir"; \
+	touch "$$dir"/*; \
+	./attrsum sum update -v "$$dir"; \
+	./attrsum check -v "$$dir"

README.md

@@ -95,7 +95,9 @@ Future improvements under consideration:
 
 * Author & maintainer: **sneak** – <sneak@sneak.berlin>
 * Issues / PRs: <https://git.eeqj.de/sneak/attrsum/>
-* Code must pass `go vet`, `go test ./...`, and `go fmt`.
+* Code must pass `make check`, which runs the tests and golangci-lint as
+  phases of the `Dockerfile` (Docker is required) and checks formatting
+  with `gofmt`.
 * No CLA; contributions are under WTFPL v2.
 
 ---

REPO_POLICIES.md

@@ -0,0 +1,679 @@
+---
+title: Repository Policies
+last_modified: 2026-10-04
+---
+
+This document covers repository structure, tooling, and workflow standards. Code
+style conventions are in separate documents:
+
+- [Code Styleguide](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/CODE_STYLEGUIDE.md)
+  (general, bash, Docker)
+- [Go](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/CODE_STYLEGUIDE_GO.md)
+- [JavaScript](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/CODE_STYLEGUIDE_JS.md)
+- [Python](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/CODE_STYLEGUIDE_PYTHON.md)
+- [Go HTTP Server Conventions](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/GO_HTTP_SERVER_CONVENTIONS.md)
+
+---
+
+- Cross-project documentation (such as this file) must include
+  `last_modified: YYYY-MM-DD` in the YAML front matter so it can be kept in sync
+  with the authoritative source as policies evolve.
+
+- **ALL external references must be pinned by cryptographic hash.** This
+  includes Docker base images, Go modules, npm packages, GitHub Actions, and
+  anything else fetched from a remote source. Version tags (`@v4`, `@latest`,
+  `:3.21`, etc.) are server-mutable and therefore remote code execution
+  vulnerabilities. The ONLY acceptable way to reference an external dependency
+  is by its content hash (Docker `@sha256:...`, Go module hash in `go.sum`, npm
+  integrity hash in lockfile, GitHub Actions `@<commit-sha>`). No exceptions.
+  This also means never `curl | bash` to install tools like pyenv, nvm, rustup,
+  etc. Instead, download a specific release archive from GitHub, verify its hash
+  (hardcoded in the Dockerfile or script), and only then install. Unverified
+  install scripts are arbitrary remote code execution. This is the single most
+  important rule in this document. Double-check every external reference in
+  every file before committing. There are zero exceptions to this rule.
+
+- Every repo with software must have a root `Makefile` with these targets:
+  `make bootstrap`, `make setup`, `make test`, `make lint`, `make fmt` (writes),
+  `make fmt-check` (read-only), `make check` (runs `test`, `lint`, `fmt-check`),
+  `make docker`, and `make hooks` (installs pre-commit hook). A model Makefile
+  is at `https://git.eeqj.de/sneak/prompts/raw/branch/main/Makefile`.
+
+- Repos follow the
+  [Scripts to Rule Them All](https://github.com/github/scripts-to-rule-them-all)
+  pattern: the implementation of each Makefile target lives in an executable
+  script in `script/` (`script/bootstrap`, `script/setup`, `script/test`,
+  `script/lint`, `script/fmt`, `script/fmt-check`, `script/check`,
+  `script/docker`), and the Makefile targets are thin shims that call them. The
+  scripts must be POSIX sh (`#!/bin/sh`, `set -eu`, no bashisms) so they run in
+  minimal containers (e.g. alpine images have no bash); locate the repo root
+  with `$(cd "$(dirname "$0")/.." && pwd -P)` and `cd` there before acting. From
+  the standard's canonical set we use `bootstrap`, `setup` (make the repo ready
+  for development after a fresh clone: runs `bootstrap`, then
+  `install-precommit`, plus any repo-specific initialization), `test`, and
+  `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 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**:
+  `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).
+
+- Always use Makefile targets (`make fmt`, `make test`, `make lint`, etc.)
+  instead of invoking the underlying tools directly. The Makefile is the single
+  source of truth for how these operations are run.
+
+- The Makefile is authoritative documentation for how the repo is used. Beyond
+  the required targets above, it should have targets for every common operation:
+  running a local development server (`make run`, `make dev`), re-initializing
+  or migrating the database (`make db-reset`, `make migrate`), building
+  artifacts (`make build`), generating code, seeding data, or anything else a
+  developer would do regularly. If someone checks out the repo and types
+  `make<tab>`, they should see every meaningful operation available. A new
+  contributor should be able to understand the entire development workflow by
+  reading the Makefile.
+
+- Every repo should have a `Dockerfile`, and it carries the repo's gates: a
+  `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.
+
+- **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 --no-cache --target lint -t "$(script/projectname)-lint" .
+    docker build --no-cache --target test -t "$(script/projectname)-test" .
+    ```
+
+    **A stage that is not the last one in the file is built only when the final
+    stage's chain depends on it, or when `--target` names it.** That is why the
+    two gates are always invoked by name here, and why the final stage carries a
+    `COPY --from=` of a harmless file from each of them: without that edge a
+    plain `docker build .` builds the last stage alone and exits 0 having linted
+    and tested nothing.
+
+    **Every `docker build` in `script/` is tagged**, here and in
+    `script/cibuild` and `script/docker`. An untagged build leaves a dangling
+    image behind on every invocation, on every developer host and every CI
+    runner; a tagged one replaces the previous image.
+
+    Inside a phase the tool is invoked directly — `golangci-lint`, `go test`,
+    `eslint`, `prettier` — never through `make lint` or `script/test`, which are
+    themselves a `docker build` and would recurse into a daemon that does not
+    exist in a build step. Formatting is the exception and stays on the host:
+    `script/fmt` writes the working tree, and `script/fmt-check` is its
+    read-only twin.
+
+    **No lint verdict may come from a host invocation of the linter.** On a
+    shared host golangci-lint reads a result cache keyed on file content rather
+    than location, so a second checkout of the same content is served the first
+    one's findings, and a host-global lock in `$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 cache, its own `TMPDIR` and
+    a digest-pinned binary, so neither is reachable.
+
+- **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.
+  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.
+
+- **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
+  `Dockerfile`:
+
+    ```dockerfile
+    # Lint phase
+    # golangci/golangci-lint:v2.x.x, YYYY-MM-DD
+    FROM golangci/golangci-lint@sha256:... AS lint
+    WORKDIR /src
+    COPY go.mod go.sum ./
+    RUN go mod download
+    COPY . .
+    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.
+    # golang:1.x, YYYY-MM-DD
+    FROM golang@sha256:... AS test
+    WORKDIR /src
+    COPY go.mod go.sum ./
+    RUN go mod download
+    COPY . .
+    RUN go test -timeout 90s -race -cover ./... || \
+        { echo "--- Rerunning with -v for details ---"; \
+          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
+    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 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/
+
+    # Runtime stage, and the last one
+    FROM alpine@sha256:...
+    COPY --from=builder /app /usr/local/bin/app
+    ENTRYPOINT ["app"]
+    ```
+
+    Key points:
+    - The lint phase uses the `golangci/golangci-lint` image directly (it has
+      both Go and the linter), so nothing needs installing.
+    - `COPY --from=<phase> /src/go.sum /dev/null` is a no-op copy whose only
+      purpose is the ordering edge. BuildKit runs stages in parallel by default,
+      and a stage nothing depends on is not built at all, so without these two
+      lines a red gate would not fail the build.
+    - 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.
+    - 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.
+
+- 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.
+  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 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. 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.
+
+- Use platform-standard formatters: `black` for Python, `prettier` for
+  JS/CSS/Markdown/HTML, `go fmt` for Go. Always use default configuration with
+  two exceptions: four-space indents (except Go), and `proseWrap: always` for
+  Markdown (hard-wrap at 80 columns). Documentation and writing repos (Markdown,
+  HTML, CSS) should also have `.prettierrc` and `.prettierignore`.
+
+- Pre-commit hook: runs `script/precommit`, which calls `script/check`. If local
+  testing is not possible in the repo, `script/precommit` may skip `script/test`
+  and run only `script/lint` and `script/fmt-check`. The hook is installed by
+  `script/install-precommit`; the Makefile must provide a `make hooks` target
+  that shims to it.
+
+- All repos with software must have tests that run via the platform-standard
+  test framework (`go test`, `pytest`, `jest`/`vitest`, etc.). If no meaningful
+  tests exist yet, add the most minimal test possible — e.g. importing the
+  module under test to verify it compiles/parses. There is no excuse for
+  `make test` to be a no-op.
+
+- `make test` must complete in under 60 seconds. That is the hard cap, and a
+  suite that exceeds it fails. Under 20 seconds is the target. A suite between
+  20 and 60 seconds is still green, but the overage must be filed as an
+  improvement bug against that repo. Add a 90-second timeout to the test
+  invocation (`go test -timeout 90s`). The backstop deliberately sits above the
+  hard cap so that it catches a genuinely hung test rather than a merely slow
+  one.
+
+- **The test command should use the conditional verbose rerun pattern.** Run
+  tests without `-v` (verbose) first. If tests fail, automatically rerun with
+  `-v` to show full output. This keeps CI logs and `docker build` output clean
+  on success (just package/suite summaries) while providing full diagnostic
+  detail on failure (every test case, every assertion). The command lives in the
+  `test` phase of the `Dockerfile`, since `script/test` builds that phase; the
+  Makefile form below is the same pattern for any repo-local invocation:
+
+    ```makefile
+    test:
+    	@<test-command> || \
+    		{ echo "--- Rerunning with -v for details ---"; \
+    		  <test-command-with-v>; exit 1; }
+    ```
+
+    Go example:
+
+    ```makefile
+    test:
+    	@go test -count=1 -timeout 90s -race -cover ./... || \
+    		{ echo "--- Rerunning with -v for details ---"; \
+    		  go test -count=1 -timeout 90s -race -v ./...; exit 1; }
+    ```
+
+    `-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.
+
+    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. That matters on a developer's machine, where this
+    target runs and the directory lasts from one run to the next. The `test`
+    phase of the `Dockerfile` needs no `-count=1`: its base image holds no
+    result for this repo's tests and nothing before its `go test` step runs a
+    test, so there is nothing to replay. `--no-cache` (above) is what makes that
+    step run on an unchanged tree.
+
+    Python example:
+
+    ```makefile
+    test:
+    	@python -m pytest || \
+    		{ echo "--- Rerunning with -v for details ---"; \
+    		  python -m pytest -v; exit 1; }
+    ```
+
+    The `exit 1` ensures the target always fails after a rerun — the first run
+    already proved the tests are broken, so the build must not pass even if a
+    flaky test happens to succeed on the second attempt. The rerun exists solely
+    for diagnostic output.
+
+- Docker builds must complete in under 5 minutes.
+
+- `make check` must not modify any files in the repo. Tests may use temporary
+  directories.
+
+- `main` must always pass `make check`, no exceptions.
+
+- Never commit secrets. `.env` files, credentials, API keys, and private keys
+  must be in `.gitignore`. No exceptions.
+
+- `.gitignore` should be comprehensive from the start: OS files (`.DS_Store`),
+  editor files (`.swp`, `*~`), in-repo agent scratch directories (`.claude/`),
+  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.
+
+- **`.dockerignore` does not use `.gitignore` semantics, and copying patterns
+  across unmodified leaves secrets in the build context.** Docker matches with
+  `moby/patternmatcher`: `filepath.Match` semantics plus a `**` extension, so
+  `*` does not cross `/` and a pattern without a leading `**/` is anchored at
+  the build-context root. A `.dockerignore` listing `.env`, `*.pem` and `*.key`
+  therefore excludes only the copies at the repository root, while `config/.env`
+  and `certs/server.key` still reach the context and can land in an image layer
+  — 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
+  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
+  secret names use character ranges — `**/*.[kK][eE][yY]`, `**/*.[pP][eE][mM]`,
+  and likewise for `.envrc` and the extensionless SSH keys. Where such a pattern
+  also catches something the build needs, re-include it with a negation
+  (`!docs/example.env`); deleting the pattern reopens the exposure for every
+  other file it covers. Fetch the standard `.dockerignore` from
+  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.dockerignore` and extend
+  it with the repo's own artifacts.
+
+- **In-repo agent scratch belongs in both files, written to each file's own
+  semantics.** `.claude/` holds one worktree per in-flight agent — an entire
+  additional checkout of the repo — so under `COPY . .` the build context
+  inflates by a multiple of the repo and another session's unreviewed work can
+  be copied into an image layer. In `.gitignore` the entry is `.claude/`,
+  unanchored. In `.dockerignore` it is `.claude`, anchored and with **no** `**/`
+  prefix, because the prefixed form would also delete any nested directory of
+  that name from the build. Anchoring carries a known gap that the canonical
+  `.dockerignore` states in its own comment, since consuming repos receive the
+  file and not the tracker: the directory is created in the agent's working
+  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:
+
+    ```sh
+    # 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 "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
+        -t "$(script/projectname)" .
+    ```
+
+    `--always` makes an untagged repo yield an abbreviated commit hash rather
+    than failing, and the `[ -n "$version" ]` line is the single place the
+    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
+    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 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
+  a probe image that does `COPY . .`, and list what actually landed
+  (`docker run --rm --entrypoint find IMAGE /app`). The `transferring context`
+  size is not a substitute: a nested secret is a few bytes, and BuildKit
+  transfers only the delta from the previous build.
+
+- **No build artifacts in version control.** Code-derived data (compiled
+  bundles, minified output, generated assets) must never be committed to the
+  repository if it can be avoided. The build process (e.g. Dockerfile, Makefile)
+  should generate these at build time. Notable exception: Go protobuf generated
+  files (`.pb.go`) ARE committed because repos need to work with `go get`, which
+  downloads code but does not execute code generation.
+
+- Never use `git add -A` or `git add .`. Always stage files explicitly by name.
+
+- Never force-push to `main`.
+
+- Make all changes on a feature branch. You can do whatever you want on a
+  feature branch.
+
+- `.golangci.yml` is standardized. The vendored copy in a consuming repo must
+  _NEVER_ be modified by an agent: fetch it from
+  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml` and keep it
+  byte-identical, so that no repo can quietly loosen its own linting. Linter
+  configuration changes are made to the canonical copy in the `prompts` repo and
+  reach consuming repos by re-vendoring; an agent may open a PR against
+  canonical, which only the user merges. One list is exempt from byte-identity,
+  because it cannot be written once for every repo: the `deny` list of the
+  `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
+  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.
+
+- **`script/bootstrap` installs a pinned tool by comparing versions, never by
+  testing presence.** An `if ! command -v <tool>; then install; fi` guard tests
+  `PATH` only, so on an already-provisioned machine the pin is inert and a
+  version bump is a silent no-op — while the Dockerfile, installing into a clean
+  image, gets the pinned version, so a local `make check` and `make docker` can
+  disagree about what the tool even is. The canonical form:
+    - compares the installed version against the pin over the **whole** version
+      token; a parser that stops at the first `-` reports `2.12.2` for a host
+      running `2.12.2-rc1` and skips the install;
+    - treats absent, non-zero, empty or unrecognised `--version` output as a
+      mismatch, so the failure direction is a redundant install and never a
+      skipped one;
+    - after installing, re-resolves the binary the way callers do — `hash -r`,
+      then through `PATH`, not through the directory the installer wrote to —
+      and fails naming the resolved path, since an install that a shadowing
+      binary hides succeeds while changing nothing any caller sees;
+    - is actually called, and prints the version on both success paths: a
+      function defined and never invoked has the same exit status and the same
+      empty output as one that worked.
+
+    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).
+
+- Use `yarn`, not `npm`.
+
+- Write all dates as YYYY-MM-DD (ISO 8601).
+
+- Simple projects should be configured with environment variables.
+
+- Dockerized web services listen on port 8080 by default, overridable with
+  `PORT`.
+
+- **HTTP/web services must be hardened for production internet exposure before
+  tagging 1.0.** This means full compliance with security best practices
+  including, without limitation, all of the following:
+    - **Security headers** on every response:
+        - `Strict-Transport-Security` (HSTS) with `max-age` of at least one year
+          and `includeSubDomains`.
+        - `Content-Security-Policy` (CSP) with a restrictive default policy
+          (`default-src 'self'` as a baseline, tightened per-resource as
+          needed). Never use `unsafe-inline` or `unsafe-eval` unless
+          unavoidable, and document the reason.
+        - `X-Frame-Options: DENY` (or `SAMEORIGIN` if framing is required).
+          Prefer the `frame-ancestors` CSP directive as the primary control.
+        - `X-Content-Type-Options: nosniff`.
+        - `Referrer-Policy: strict-origin-when-cross-origin` (or stricter).
+        - `Permissions-Policy` restricting access to browser features the
+          application does not use (camera, microphone, geolocation, etc.).
+    - **Request and response limits:**
+        - Maximum request body size enforced on all endpoints (e.g. Go
+          `http.MaxBytesReader`). Choose a sane default per-route; never accept
+          unbounded input.
+        - Maximum response body size where applicable (e.g. paginated APIs).
+        - `ReadTimeout` and `ReadHeaderTimeout` on the `http.Server` to defend
+          against slowloris attacks.
+        - `WriteTimeout` on the `http.Server`.
+        - `IdleTimeout` on the `http.Server`.
+        - Per-handler execution time limits via `context.WithTimeout` or
+          chi/stdlib `middleware.Timeout`.
+    - **Authentication and session security:**
+        - Rate limiting on password-based authentication endpoints. API keys are
+          high-entropy and not susceptible to brute force, so they are exempt.
+        - CSRF tokens on all state-mutating HTML forms. API endpoints
+          authenticated via `Authorization` header (Bearer token, API key) are
+          exempt because the browser does not attach these automatically.
+        - Passwords stored using bcrypt, scrypt, or argon2 — never plain-text,
+          MD5, or SHA.
+        - Session cookies set with `HttpOnly`, `Secure`, and `SameSite=Lax` (or
+          `Strict`) attributes.
+    - **Reverse proxy awareness:**
+        - True client IP detection when behind a reverse proxy
+          (`X-Forwarded-For`, `X-Real-IP`). The application must accept
+          forwarded headers only from a configured set of trusted proxy
+          addresses — never trust `X-Forwarded-For` unconditionally.
+    - **CORS:**
+        - Authenticated endpoints must restrict `Access-Control-Allow-Origin` to
+          an explicit allowlist of known origins. Wildcard (`*`) is acceptable
+          only for public, unauthenticated read-only APIs.
+    - **Error handling:**
+        - Internal errors must never leak stack traces, SQL queries, file paths,
+          or other implementation details to the client. Return generic error
+          messages in production; detailed errors only when `DEBUG` is enabled.
+    - **TLS:**
+        - Services never terminate TLS directly. They are always deployed behind
+          a TLS-terminating reverse proxy. The service itself listens on plain
+          HTTP. However, HSTS headers and `Secure` cookie flags must still be
+          set by the application so that the browser enforces HTTPS end-to-end.
+
+    This list is non-exhaustive. Apply defense-in-depth: if a standard security
+    hardening measure exists for HTTP services and is not listed here, it is
+    still expected. When in doubt, harden.
+
+- `README.md` is the primary documentation. Required sections:
+    - **Description**: First line must include the project name, purpose,
+      category (web server, SPA, CLI tool, etc.), license, and author. Example:
+      "µPaaS is an MIT-licensed Go web application by @sneak that receives
+      git-frontend webhooks and deploys applications via Docker in realtime."
+    - **Getting Started**: Copy-pasteable install/usage code block.
+    - **Entrypoints**: Opens by stating that the repo adheres to the
+      [Scripts to Rule Them All](https://github.com/github/scripts-to-rule-them-all)
+      standard (with that link), then documents each provided `script/`
+      entrypoint and its purpose.
+    - **Rationale**: Why does this exist?
+    - **Design**: How is the program structured?
+    - **TODO**: Update meticulously, even between commits. When planning, put
+      the todo list in the README so a new agent can pick up where the last one
+      left off.
+    - **License**: MIT, GPL, or WTFPL. Ask the user for new projects. Include a
+      `LICENSE` file in the repo root and a License section in the README.
+    - **Author**: [@sneak](https://sneak.berlin).
+
+- First commit of a new repo should contain only `README.md`.
+
+- Go module root: `sneak.berlin/go/<name>`. Always run `go mod tidy` before
+  committing.
+
+- Use SemVer.
+
+- Database migrations live in `internal/db/migrations/` and must be embedded in
+  the binary.
+    - `000_migration.sql` — contains ONLY the creation of the migrations
+      tracking table itself. Nothing else.
+    - `001_schema.sql` — the full application schema.
+    - **Pre-1.0.0:** never add additional migration files (002, 003, etc.).
+      There is no installed base to migrate. Edit `001_schema.sql` directly.
+    - **Post-1.0.0:** add new numbered migration files for each schema change.
+      Never edit existing migrations after release.
+
+- All repos should have an `.editorconfig` enforcing the project's indentation
+  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:
+    - `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
+      `cmd/`
+    - `configs/` — configuration templates and examples
+    - `deploy/` — deployment manifests (k8s, compose, terraform)
+    - `docs/` — documentation and markdown (README.md stays in root)
+    - `internal/` — Go internal packages
+    - `internal/db/migrations/` — database migrations
+    - `pkg/` — Go library packages
+    - `share/` — systemd units, data files
+    - `static/` — static assets (images, fonts, etc.)
+    - `web/` — web frontend source
+
+- When setting up a new repo, files from the `prompts` repo may be used as
+  templates. Fetch them from
+  `https://git.eeqj.de/sneak/prompts/raw/branch/main/<path>`.
+
+- New repos must contain at minimum:
+    - `README.md`, `.git`, `.gitignore`, `.editorconfig`
+    - `LICENSE`, `REPO_POLICIES.md` (copy from the `prompts` repo)
+    - `Makefile`
+    - `script/` entrypoints (`bootstrap`, `setup`, `projectname`, `test`,
+      `lint`, `fmt`, `fmt-check`, `check`, `docker`, `cibuild`, `precommit`,
+      `install-precommit`)
+    - `Dockerfile`, `.dockerignore`
+    - `.gitea/workflows/check.yml`
+    - 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.

TODO.md

@@ -17,15 +17,44 @@ have landed since the tag.
 
 # Next Step
 
-Policy scaffold commit: add LICENSE, REPO_POLICIES.md, .editorconfig,
+Restructure README.md into the standard sections: Description, Getting
-.golangci.yml, and a comprehensive .gitignore (currently only the
+Started, Entrypoints, Rationale, Design, TODO, License, Author (Getting
-attrsum binary), and extend the Makefile (only test/build/clean/try
+Started, Why?, TODO, License exist; Description, Entrypoints, Design,
-today) with lint, fmt, fmt-check, check, and hooks targets. Fix the try
+Author are missing)
-target to use a temp fixture instead of the hardcoded
-$(HOME)/Documents/_SYSADMIN/cyberdyne path.
 
 # Completed Steps
 
+* 2026-10-06: canonical files re-vendored from `sneak/prompts` at
+    `dd4027b`: `REPO_POLICIES.md` and `.editorconfig` added;
+    `.dockerignore`, `.gitignore`, `.golangci.yml` and the workflow
+    refreshed, keeping this repo's own entries and `fetch-depth: 0`;
+    the lint phase runs golangci-lint v2.14.0; `script/fmt` runs
+    goimports with `go run` at its pinned commit instead of
+    `script/bootstrap` installing it
+* 2026-10-06: a path that `--exclude` or `--exclude-dotfiles` excludes
+    is skipped even when it cannot be read, so an excluded directory
+    that cannot be listed no longer fails the run
+* 2026-10-06: lint and test run as phases of the `Dockerfile`, and the
+    build stage depends on both; `script/lint` and `script/test` each
+    build their phase with `--no-cache`; `script/cibuild` bootstraps,
+    runs `script/check`, then builds the image; golangci-lint is no
+    longer installed on the host
+* 2026-10-06: `check --continue` keeps going past a file or directory
+    it cannot read: it counts it as failed, prints the error and the
+    path on stderr, and checks the rest of the tree
+* 2026-10-05: golangci-lint settings take effect: canonical
+    `.golangci.yml` (v2 layout, settings under `linters.settings`),
+    golangci-lint pinned at v2.12.2 in `Dockerfile` and
+    `script/bootstrap`, and the code fixed for what the settings now
+    report (long lines in `attrsum.go` rewrapped)
+* 2026-10-05: `make try` runs on three small files in a temporary
+    directory that it removes afterwards, also when a step fails,
+    instead of on a fixed directory on one person's machine
+* 2026-10-02: `attrsum --version` reports the git tag or short commit,
+    stamped by `make build` and by a plain `docker build .` of a clone;
+    `.dockerignore` sends `.git` without `.git/config` and keeps a
+    host-built `attrsum` out; CI checks out full history so it stamps
+    the same version
 * 2026-02-02: correctness pass: track actual bytes read instead of
     stale file size, atomic failure tracking in ProcessCheck, detect
     file modification during checksum (TOCTOU), propagate countFiles
@@ -39,13 +68,8 @@ $(HOME)/Documents/_SYSADMIN/cyberdyne path.
 
 # Future Steps
 
-* Add Dockerfile and .dockerignore that run make check, images pinned
+* Add a `LICENSE` file matching the README's WTFPL v2; sneak's to add,
-    by sha256, plus a Makefile docker target
+    not an agent's
-* Add .gitea/workflows/check.yml
-* Restructure README.md into the standard sections: Description,
-    Getting Started, Rationale, Design, TODO, License, Author (Getting
-    Started, Why?, TODO, License exist; Description, Design, Author are
-    missing)
 * Tag a patch release to ship the 2026-02-02 correctness fixes
 * Dry-run mode (--dry-run, -n): show what would be done without making
     changes (from README TODO)

attrsum.go

@@ -36,6 +36,10 @@ const (
 	progressThrottle = 250 * time.Millisecond
 )
 
+// Version is the git tag or short commit, set at link time with -X by
+// `make build`. A build that does not set it reports dev.
+var Version = "dev" //nolint:gochecknoglobals // set at link time with -X
+
 // Sentinel errors returned by the command implementations.
 var (
 	errNoPaths           = errors.New("no paths provided")
@@ -72,7 +76,8 @@ func (s *Stats) Print(opts *options, operation string) {
 		return
 	}
 
-	fmt.Fprintf(os.Stderr, "\n%s complete: %d files processed, %d skipped, %d failed, %s bytes in %s\n",
+	fmt.Fprintf(os.Stderr,
+		"\n%s complete: %d files processed, %d skipped, %d failed, %s bytes in %s\n",
 		operation,
 		s.FilesProcessed,
 		s.FilesSkipped,
@@ -101,8 +106,9 @@ func main() {
 	opts := &options{}
 
 	rootCmd := &cobra.Command{
-		Use:   "attrsum",
+		Use:     "attrsum",
-		Short: "Compute and verify file checksums via xattrs",
+		Short:   "Compute and verify file checksums via xattrs",
+		Version: Version,
 	}
 	rootCmd.SilenceUsage = true
 	rootCmd.SilenceErrors = true
@@ -166,12 +172,16 @@ func expandPaths(args []string) ([]string, error) {
 }
 
 // processFunc processes a single path within a command's run loop.
-type processFunc func(opts *options, path string, stats *Stats, bar *progressbar.ProgressBar) error
+type processFunc func(
+	opts *options, path string, stats *Stats, bar *progressbar.ProgressBar,
+) error
 
 // countAndBar counts the files under paths and returns a progress bar sized
 // to that total. It always returns either a non-nil bar or a non-nil error.
-func countAndBar(opts *options, paths []string, desc string) (*progressbar.ProgressBar, error) {
+func countAndBar(
-	total, err := countFilesMultiple(opts, paths)
+	opts *options, paths []string, desc string, cont bool,
+) (*progressbar.ProgressBar, error) {
+	total, err := countFilesMultiple(opts, paths, cont)
 	if err != nil {
 		return nil, err
 	}
@@ -188,7 +198,9 @@ func finishBar(bar *progressbar.ProgressBar) {
 
 // runOverPaths runs process over each path, sharing the progress/stats
 // bookkeeping common to the sum-add, sum-update and clear commands.
-func runOverPaths(opts *options, args []string, desc, op string, process processFunc) error {
+func runOverPaths(
+	opts *options, args []string, desc, op string, process processFunc,
+) error {
 	paths, err := expandPaths(args)
 	if err != nil {
 		return err
@@ -199,7 +211,7 @@ func runOverPaths(opts *options, args []string, desc, op string, process process
 	var bar *progressbar.ProgressBar
 
 	if !opts.quiet {
-		bar, err = countAndBar(opts, paths, desc)
+		bar, err = countAndBar(opts, paths, desc, false)
 		if err != nil {
 			return err
 		}
@@ -253,46 +265,54 @@ func newSumCmd(opts *options) *cobra.Command {
 	return cmd
 }
 
-func processSumAdd(opts *options, dir string, stats *Stats, bar *progressbar.ProgressBar) error {
+func processSumAdd(
-	return walkAndProcess(opts, dir, stats, bar, func(p string, info os.FileInfo, s *Stats) error {
+	opts *options, dir string, stats *Stats, bar *progressbar.ProgressBar,
-		if hasXattr(p, checksumKey) {
+) error {
-			atomic.AddInt64(&s.FilesSkipped, 1)
+	return walkAndProcess(opts, dir, false, stats, bar,
+		func(p string, info os.FileInfo, s *Stats) error {
+			if hasXattr(p, checksumKey) {
+				atomic.AddInt64(&s.FilesSkipped, 1)
 
-			return nil
+				return nil
-		}
+			}
 
-		err := writeChecksumAndTime(opts, p, info, s)
+			err := writeChecksumAndTime(opts, p, info, s)
-		if err != nil {
+			if err != nil {
-			atomic.AddInt64(&s.FilesFailed, 1)
-
-			return err
-		}
-
-		return nil
-	})
-}
-
-func processSumUpdate(opts *options, dir string, stats *Stats, bar *progressbar.ProgressBar) error {
-	return walkAndProcess(opts, dir, stats, bar, func(p string, info os.FileInfo, s *Stats) error {
-		t, err := readSumTime(p)
-		if err != nil || info.ModTime().After(t) {
-			werr := writeChecksumAndTime(opts, p, info, s)
-			if werr != nil {
 				atomic.AddInt64(&s.FilesFailed, 1)
 
-				return werr
+				return err
 			}
 
 			return nil
-		}
+		})
-
-		atomic.AddInt64(&s.FilesSkipped, 1)
-
-		return nil
-	})
 }
 
-func writeChecksumAndTime(opts *options, path string, info os.FileInfo, stats *Stats) error {
+func processSumUpdate(
+	opts *options, dir string, stats *Stats, bar *progressbar.ProgressBar,
+) error {
+	return walkAndProcess(opts, dir, false, stats, bar,
+		func(p string, info os.FileInfo, s *Stats) error {
+			t, err := readSumTime(p)
+			if err != nil || info.ModTime().After(t) {
+				werr := writeChecksumAndTime(opts, p, info, s)
+				if werr != nil {
+					atomic.AddInt64(&s.FilesFailed, 1)
+
+					return werr
+				}
+
+				return nil
+			}
+
+			atomic.AddInt64(&s.FilesSkipped, 1)
+
+			return nil
+		})
+}
+
+func writeChecksumAndTime(
+	opts *options, path string, info os.FileInfo, stats *Stats,
+) error {
 	// Record mtime before hashing to detect modifications during hash.
 	mtimeBefore := info.ModTime()
 
@@ -363,24 +383,27 @@ func newClearCmd(opts *options) *cobra.Command {
 	}
 }
 
-func processClear(opts *options, dir string, stats *Stats, bar *progressbar.ProgressBar) error {
+func processClear(
-	return walkAndProcess(opts, dir, stats, bar, func(p string, info os.FileInfo, s *Stats) error {
+	opts *options, dir string, stats *Stats, bar *progressbar.ProgressBar,
-		cleared, err := clearOne(opts, p)
+) error {
-		if err != nil {
+	return walkAndProcess(opts, dir, false, stats, bar,
-			atomic.AddInt64(&s.FilesFailed, 1)
+		func(p string, info os.FileInfo, s *Stats) error {
+			cleared, err := clearOne(opts, p)
+			if err != nil {
+				atomic.AddInt64(&s.FilesFailed, 1)
 
-			return err
+				return err
-		}
+			}
 
-		if cleared {
+			if cleared {
-			atomic.AddInt64(&s.FilesProcessed, 1)
+				atomic.AddInt64(&s.FilesProcessed, 1)
-			atomic.AddInt64(&s.BytesProcessed, info.Size())
+				atomic.AddInt64(&s.BytesProcessed, info.Size())
-		} else {
+			} else {
-			atomic.AddInt64(&s.FilesSkipped, 1)
+				atomic.AddInt64(&s.FilesSkipped, 1)
-		}
+			}
 
-		return nil
+			return nil
-	})
+		})
 }
 
 // clearOne removes both checksum xattrs from a single path, reporting
@@ -428,7 +451,8 @@ func newCheckCmd(opts *options) *cobra.Command {
 			return runCheck(opts, a, cont)
 		},
 	}
-	cmd.Flags().BoolVar(&cont, "continue", false, "continue after errors and report each file")
+	cmd.Flags().BoolVar(&cont, "continue", false,
+		"continue after errors and report each file")
 
 	return cmd
 }
@@ -444,7 +468,7 @@ func runCheck(opts *options, args []string, cont bool) error {
 	var bar *progressbar.ProgressBar
 
 	if !opts.quiet {
-		bar, err = countAndBar(opts, paths, "Verifying checksums")
+		bar, err = countAndBar(opts, paths, "Verifying checksums", cont)
 		if err != nil {
 			return err
 		}
@@ -472,13 +496,16 @@ func runCheck(opts *options, args []string, cont bool) error {
 	return finalErr
 }
 
-func processCheck(opts *options, dir string, cont bool, stats *Stats, bar *progressbar.ProgressBar) error {
+func processCheck(
+	opts *options, dir string, cont bool, stats *Stats, bar *progressbar.ProgressBar,
+) error {
 	// Track initial failed count to detect failures during this walk.
 	initialFailed := atomic.LoadInt64(&stats.FilesFailed)
 
-	err := walkAndProcess(opts, dir, stats, bar, func(p string, _ os.FileInfo, s *Stats) error {
+	err := walkAndProcess(opts, dir, cont, stats, bar,
-		return checkOne(opts, p, cont, s)
+		func(p string, _ os.FileInfo, s *Stats) error {
-	})
+			return checkOne(opts, p, cont, s)
+		})
 	if err != nil {
 		if errors.Is(err, errVerification) {
 			return errVerification
@@ -500,7 +527,7 @@ func checkOne(opts *options, p string, cont bool, s *Stats) error {
 	exp, err := xattr.Get(p, checksumKey)
 	if err != nil {
 		if !errors.Is(err, xattr.ENOATTR) {
-			return err
+			return unreadable(cont, s, err)
 		}
 
 		return missingChecksum(opts, p, cont, s)
@@ -508,9 +535,7 @@ func checkOne(opts *options, p string, cont bool, s *Stats) error {
 
 	act, bytesRead, err := fileMultihash(p)
 	if err != nil {
-		atomic.AddInt64(&s.FilesFailed, 1)
+		return unreadable(cont, s, err)
-
-		return err
 	}
 
 	ok := bytes.Equal(exp, act)
@@ -546,6 +571,21 @@ func missingChecksum(opts *options, p string, cont bool, s *Stats) error {
 	return errVerification
 }
 
+// unreadable counts a file or directory that could not be read as failed.
+// With --continue it prints err, which names the path, to stderr and
+// returns nil so the walk goes on; otherwise it returns err.
+func unreadable(cont bool, s *Stats, err error) error {
+	atomic.AddInt64(&s.FilesFailed, 1)
+
+	if !cont {
+		return err
+	}
+
+	log.Print(err)
+
+	return nil
+}
+
 // reportCheck prints a per-file verification result when verbose output is on.
 func reportCheck(opts *options, p, actual string, ok bool) {
 	if !opts.verbose || opts.quiet {
@@ -565,12 +605,24 @@ func reportCheck(opts *options, p, actual string, ok bool) {
 ///////////////////////////////////////////////////////////////////////////////
 
 // countFiles counts the total number of regular files that will be processed.
-func countFiles(opts *options, root string) (int64, error) {
+// With cont, a path it cannot read is left out of the count instead of ending
+// it; the walk that follows reports that path as failed.
+func countFiles(opts *options, root string, cont bool) (int64, error) {
 	var count int64
 
 	root = filepath.Clean(root)
 
 	err := filepath.Walk(root, func(p string, info os.FileInfo, err error) error {
+		// An excluded path is skipped whatever went wrong reading it.
+		rel, _ := filepath.Rel(root, p)
+		if err != nil && shouldExclude(opts, rel) {
+			return nil
+		}
+
+		if err != nil && cont {
+			return nil
+		}
+
 		if err != nil {
 			return err
 		}
@@ -581,7 +633,6 @@ func countFiles(opts *options, root string) (int64, error) {
 			return nil
 		}
 
-		rel, _ := filepath.Rel(root, p)
 		if shouldExclude(opts, rel) {
 			if info.IsDir() {
 				return filepath.SkipDir
@@ -605,11 +656,11 @@ func countFiles(opts *options, root string) (int64, error) {
 }
 
 // countFilesMultiple counts files across multiple roots.
-func countFilesMultiple(opts *options, roots []string) (int64, error) {
+func countFilesMultiple(opts *options, roots []string, cont bool) (int64, error) {
 	var total int64
 
 	for _, root := range roots {
-		count, err := countFiles(opts, root)
+		count, err := countFiles(opts, root, cont)
 		if err != nil {
 			return total, err
 		}
@@ -645,6 +696,7 @@ func newProgressBar(total int64, description string) *progressbar.ProgressBar {
 func walkAndProcess(
 	opts *options,
 	root string,
+	cont bool,
 	stats *Stats,
 	bar *progressbar.ProgressBar,
 	fn func(string, os.FileInfo, *Stats) error,
@@ -652,8 +704,14 @@ func walkAndProcess(
 	root = filepath.Clean(root)
 
 	return filepath.Walk(root, func(p string, info os.FileInfo, err error) error {
+		// An excluded path is skipped whatever went wrong reading it.
+		rel, _ := filepath.Rel(root, p)
+		if err != nil && shouldExclude(opts, rel) {
+			return nil
+		}
+
 		if err != nil {
-			return err
+			return unreadable(cont, stats, err)
 		}
 
 		skip, skipErr := walkSkip(opts, root, p, info)
@@ -742,7 +800,8 @@ func hasXattr(path, key string) bool {
 func fileMultihash(path string) ([]byte, int64, error) {
 	// The path is supplied by the operator as the tree to checksum; reading
 	// it is the entire purpose of the tool.
-	f, err := os.Open(path) //nolint:gosec // G304: operator-specified path is the intended input
+	//nolint:gosec // G304: operator-specified path is the intended input
+	f, err := os.Open(path)
 	if err != nil {
 		return nil, 0, err
 	}

attrsum_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"strings"
@@ -213,6 +214,54 @@ func TestExcludeDotfilesAndPatterns(t *testing.T) {
 	}
 }
 
+func TestExcludeUnreadableDir(t *testing.T) {
+	t.Parallel()
+
+	opts := &options{excludePatterns: []string{"locked"}}
+	dir := t.TempDir()
+	skipIfNoXattr(t, dir)
+
+	keep := writeFile(t, dir, "keep.txt", "keep")
+	hidden := writeFile(t, dir, "locked/a.txt", "hidden")
+
+	// The excluded directory cannot be listed.
+	sub := filepath.Join(dir, "locked")
+
+	err := os.Chmod(sub, noPerm)
+	if err != nil {
+		t.Fatalf("chmod dir: %v", err)
+	}
+
+	defer func() { _ = os.Chmod(sub, dirPerm) }()
+
+	err = processSumAdd(opts, dir, newTestStats(), nil)
+	if err != nil {
+		t.Fatalf("add: %v", err)
+	}
+
+	_, err = xattr.Get(keep, checksumKey)
+	if err != nil {
+		t.Fatalf("expected xattr on keep.txt: %v", err)
+	}
+
+	// Without --quiet, runCheck counts the files for the progress bar
+	// before it checks any, so this also covers the count.
+	err = runCheck(opts, []string{dir}, false)
+	if err != nil {
+		t.Fatalf("check: %v", err)
+	}
+
+	err = os.Chmod(sub, dirPerm)
+	if err != nil {
+		t.Fatalf("chmod dir back: %v", err)
+	}
+
+	_, err = xattr.Get(hidden, checksumKey)
+	if err == nil {
+		t.Fatalf("locked/a.txt should have been excluded")
+	}
+}
+
 func TestSkipBrokenSymlink(t *testing.T) {
 	t.Parallel()
 
@@ -271,3 +320,59 @@ func TestPermissionErrors(t *testing.T) {
 		t.Fatalf("expected permission error on check, got nil")
 	}
 }
+
+func TestCheckContinuePastUnreadable(t *testing.T) {
+	t.Parallel()
+
+	opts := &options{}
+	dir := t.TempDir()
+	skipIfNoXattr(t, dir)
+
+	writeFile(t, dir, "a.txt", "one")
+	secret := writeFile(t, dir, "b.txt", "two")
+	writeFile(t, dir, "c/d.txt", "three")
+	writeFile(t, dir, "e.txt", "four")
+
+	err := processSumAdd(opts, dir, newTestStats(), nil)
+	if err != nil {
+		t.Fatalf("add: %v", err)
+	}
+
+	// An unreadable file and an unlistable directory sit between the
+	// readable files a.txt and e.txt.
+	sub := filepath.Join(dir, "c")
+
+	err = os.Chmod(secret, noPerm)
+	if err != nil {
+		t.Fatalf("chmod file: %v", err)
+	}
+
+	defer func() { _ = os.Chmod(secret, filePerm) }()
+
+	err = os.Chmod(sub, noPerm)
+	if err != nil {
+		t.Fatalf("chmod dir: %v", err)
+	}
+
+	defer func() { _ = os.Chmod(sub, dirPerm) }()
+
+	stats := newTestStats()
+
+	err = processCheck(opts, dir, true, stats, nil)
+	if !errors.Is(err, errVerification) {
+		t.Fatalf("expected verification error, got %v", err)
+	}
+
+	if stats.FilesProcessed != 2 || stats.FilesFailed != 2 {
+		t.Fatalf("expected 2 verified and 2 failed, got %d and %d",
+			stats.FilesProcessed, stats.FilesFailed)
+	}
+
+	// Without --quiet, runCheck counts the files for the progress bar
+	// before it checks any, so the count reaches the unlistable directory
+	// first.
+	err = runCheck(opts, []string{dir}, true)
+	if !errors.Is(err, errVerification) {
+		t.Fatalf("expected verification error from runCheck, got %v", err)
+	}
+}

script/bootstrap

@@ -3,18 +3,13 @@
 # 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.
-# golangci-lint and goimports are installed via `go install` at the same
+# goimports is not installed: script/fmt runs it with `go run` at a
-# pinned commits the Dockerfile uses (never "latest").
+# pinned commit. The linter is not installed: it runs only as the lint
+# phase of the Dockerfile.
 set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
-# Pinned versions, 2026-07-07 (same pins as the Dockerfile)
-# golangci-lint v2.10.1
-GOLANGCI_LINT_REF="github.com/golangci/golangci-lint/v2/cmd/golangci-lint@5d1e709b7be35cb2025444e19de266b056b7b7ee"
-# goimports v0.42.0
-GOIMPORTS_REF="golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0"
-
 PKGMGR=""
 SUDO=""
 APT_UPDATED=""
@@ -69,11 +64,6 @@ main() {
     if missing make; then pkg_install gnumake make make make; fi
     if missing go; then pkg_install go golang go go; fi
 
-    # Lint/format tools, pinned via go install (installs into
-    # "$(go env GOPATH)/bin"; ensure that is on your PATH).
-    if missing golangci-lint; then go install "$GOLANGCI_LINT_REF"; fi
-    if missing goimports; then go install "$GOIMPORTS_REF"; fi
-
     go mod download
 
     echo "bootstrap complete"

script/check

@@ -1,6 +1,8 @@
 #!/bin/sh
 # script/check: run all checks (test, lint, fmt-check). Our own
-# extension to scripts-to-rule-them-all. Must not modify any files.
+# extension to scripts-to-rule-them-all. test and lint are Docker
+# phases; fmt-check is native, because a formatter writes the working
+# tree. Must not modify any files.
 set -eu
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"

script/cibuild

@@ -1,13 +1,28 @@
 #!/bin/sh
-# script/cibuild: run the CI build. The Dockerfile runs make check, so
+# script/cibuild: run the CI build. It bootstraps first: a CI runner
-# a successful build implies all checks pass.
+# checks out and runs this and nothing else, and script/fmt-check runs
+# the formatter on the host, which a pristine checkout cannot do.
+# --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
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build .
+    "$SCRIPT_DIR/bootstrap"
+    "$SCRIPT_DIR/check"
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. The VERSION build argument takes precedence over
+    # the version a build stage derives from the .git in the context.
+    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
+    [ -n "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
+        -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/docker

@@ -1,6 +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.
+# --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 "$0")" && pwd -P)"
@@ -8,7 +10,15 @@ ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    docker build -t "$("$SCRIPT_DIR/projectname")" .
+    # Own line: a failing command substitution inside an argument does
+    # not trip `set -e`, so the inline form degrades silently to an
+    # empty constant. The VERSION build argument takes precedence over
+    # the version a build stage derives from the .git in the context.
+    version="$(git describe --tags --always --dirty 2>/dev/null || true)"
+    [ -n "$version" ] || version="unknown"
+    docker build --no-cache \
+        --build-arg VERSION="$version" \
+        -t "$("$SCRIPT_DIR/projectname")" .
 }
 
 main "$@"

script/fmt

@@ -4,10 +4,14 @@ set -eu
 
 ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
+# goimports v0.42.0, 2026-10-05. Run with `go run` at this commit rather
+# than installed, so it is always this version, whatever is on PATH.
+GOIMPORTS_REF="golang.org/x/tools/cmd/goimports@009367f5c17a8d4c45a961a3a509277190a9a6f0"
+
 main() {
     cd "$ROOT"
     gofmt -s -w .
-    goimports -w .
+    go run "$GOIMPORTS_REF" -w .
 }
 
 main "$@"

script/lint

@@ -1,12 +1,23 @@
 #!/bin/sh
-# script/lint: run the linter.
+# script/lint: run the linter. Linting is a phase of the Dockerfile and
+# this builds that phase alone; the linter is never installed or run on
+# a developer host, where a shared result cache and a host-global lock
+# make its answer untrustworthy.
+#
+# The phase is not the last stage in the file, so it is built only when
+# --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
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    golangci-lint run --config .golangci.yml ./...
+    docker build --no-cache \
+        --target lint \
+        -t "$("$SCRIPT_DIR/projectname")-lint" .
 }
 
 main "$@"

script/test

@@ -1,12 +1,19 @@
 #!/bin/sh
-# script/test: run the test suite.
+# 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, --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
 
-ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    go test -v -race -timeout 30s -cover ./...
+    docker build --no-cache \
+        --target test \
+        -t "$("$SCRIPT_DIR/projectname")-test" .
 }
 
 main "$@"