Update golangci-lint to v2.12.2 with canonical config

Add the canonical .golangci.yml (v2 layout, default: all with the
standard disable list) and pin golangci-lint v2.12.2 in the Makefile
deps target using the v2 module path, replacing the @latest install on
the old v1 path. The Dockerfile lint stage already pinned the v2.12.2
alpine image by digest and is unchanged.

Fix all issues surfaced by the strict config:

- err113: introduce wrapped static sentinel errors
- gocognit/funlen/nestif: split ExtractDay, Run, DumpAndCompress,
  VerifyOutput, and the CLI flag parsing into smaller helpers
- noctx: use ExecContext/QueryContext/BeginTx and CommandContext
- noinlineerr: replace inline if-err assignments with plain ones
- wsl_v5/nlreturn: add required blank lines
- lll: wrap long lines and SQL strings
- gosec: filepath.Clean on file open/create; bounded uint64
  conversion in CheckFreeSpace; named output dir permission constant
- mnd: use unix.FADV_* constants and named size constants
- revive: add package and exported symbol comments
- testpackage/paralleltest: move smoke test to bsdaily_test with
  t.Parallel()
- nonamedreturns: drop non-error named returns

The remaining nolint directives (gosec subprocess launches with
internal paths, unqueryvet full-row SELECT * copies whose schema is
defined by the source database) are each justified inline.

.gitea/workflows/check.yml

@@ -11,4 +11,4 @@ jobs:
       # actions/checkout v4, 2024-09-16
       - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5
       - name: Build and check
-        run: docker build .
+        run: script/cibuild

.golangci.yml

@@ -0,0 +1,34 @@
+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
+  disable:
+    # Genuinely incompatible with project patterns
+    - exhaustruct      # Requires all struct fields
+    - depguard         # Dependency allow/block lists
+    - 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
+  settings:
+    lll:
+      line-length: 88
+    funlen:
+      lines: 80
+      statements: 50
+    cyclop:
+      max-complexity: 15
+    dupl:
+      threshold: 100
+
+issues:
+  max-issues-per-linter: 0
+  max-same-issues: 0

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all check test lint fmt fmt-check build clean deps test-coverage test-integration install release release-snapshot docker hooks
+.PHONY: all bootstrap setup check test lint fmt fmt-check build clean deps test-coverage test-integration install release release-snapshot docker hooks
 
 # Version number
 VERSION := 0.1.0-dev
@@ -6,24 +6,33 @@ VERSION := 0.1.0-dev
 # Default target
 all: bsdaily
 
-# Combined pre-commit/CI gate: lint, format check, then tests.
+# Install all development dependencies.
-check: lint fmt-check test
+bootstrap:
+	@script/bootstrap
+
+# Prepare a fresh clone: bootstrap plus pre-commit hook.
+setup:
+	@script/setup
+
+# Combined pre-commit/CI gate: tests, lint, format check.
+check:
+	@script/check
 
 # Run tests only.
 test:
-	go test -race -timeout 30s ./...
+	@script/test
 
 # Check if code is formatted (read-only).
 fmt-check:
-	@test -z "$$(gofmt -l .)" || (echo "Files not formatted:" && gofmt -l . && exit 1)
+	@script/fmt-check
 
 # Format code.
 fmt:
-	go fmt ./...
+	@script/fmt
 
 # Run linter only.
 lint:
-	golangci-lint run ./...
+	@script/lint
 
 # Build binary (pure Go; no CGO required since we use modernc.org/sqlite).
 bsdaily: internal/*/*.go cmd/bsdaily/*.go
@@ -37,7 +46,7 @@ clean:
 # Install dependencies.
 deps:
 	go mod download
-	go install github.com/golangci/golangci-lint/cmd/golangci-lint@latest
+	go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.12.2
 
 # Run tests with coverage.
 test-coverage:
@@ -61,11 +70,8 @@ release-snapshot:
 
 # Build Docker image.
 docker:
-	docker build -t bsdaily .
+	@script/docker
 
 # Install pre-commit hook.
 hooks:
-	@printf '#!/bin/sh\nset -e\n' > .git/hooks/pre-commit
+	@script/install-precommit
-	@printf 'go mod tidy\ngo fmt ./...\ngit diff --exit-code -- go.mod go.sum || { echo "go mod tidy changed files; please stage and retry"; exit 1; }\n' >> .git/hooks/pre-commit
-	@printf 'make check\n' >> .git/hooks/pre-commit
-	@chmod +x .git/hooks/pre-commit

README.md

@@ -45,6 +45,35 @@ requests](https://git.eeqj.de/sneak/bsdaily/pulls) and pass CI to be merged.
 See [`REPO_POLICIES.md`](REPO_POLICIES.md) for detailed coding standards,
 tooling requirements, and workflow conventions.
 
+# Entrypoints
+
+This repository adheres to the
+[Scripts to Rule Them All](https://github.com/github/scripts-to-rule-them-all)
+standard: normalized scripts in `script/` are the entrypoints for the
+development workflow, and the Makefile targets are thin shims that call
+them. We provide:
+
+- `script/bootstrap` — install all development dependencies (go,
+  golangci-lint, Go module download)
+- `script/setup` — make a fresh clone ready for development: runs
+  `script/bootstrap`, then `script/install-precommit`
+- `script/projectname` — print the project name (used for the Docker
+  image tag)
+- `script/test` — run the test suite (verbose rerun on failure)
+- `script/lint` — run `golangci-lint run ./...`
+- `script/fmt` — format all code (writes)
+- `script/fmt-check` — check formatting (read-only)
+- `script/check` — run `script/test`, `script/lint`, and
+  `script/fmt-check`
+- `script/docker` — build the Docker image tagged via
+  `script/projectname`
+- `script/cibuild` — CI entrypoint: `docker build .` (the Dockerfile
+  runs the checks)
+- `script/precommit` — pre-commit gate: `go mod tidy` + `go fmt` (must
+  not change files), then `script/check`
+- `script/install-precommit` — install the git pre-commit hook that
+  runs `script/precommit`
+
 # Problem Statement
 
 A Bluesky firehose ingester writes every observed post (and associated

REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-03-18
+last_modified: 2026-07-06
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -34,10 +34,46 @@ style conventions are in separate documents:
   every file before committing. There are zero exceptions to this rule.
 
 - Every repo with software must have a root `Makefile` with these targets:
-  `make test`, `make lint`, `make fmt` (writes), `make fmt-check` (read-only),
+  `make bootstrap`, `make setup`, `make test`, `make lint`, `make fmt` (writes),
-  `make check` (prereqs: `test`, `lint`, `fmt-check`), `make docker`, and
+  `make fmt-check` (read-only), `make check` (runs `test`, `lint`, `fmt-check`),
-  `make hooks` (installs pre-commit hook). A model Makefile is at
+  `make docker`, and `make hooks` (installs pre-commit hook). A model Makefile
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/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 and runs `docker build .`; the Gitea workflow calls it. 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
@@ -57,7 +93,11 @@ style conventions are in separate documents:
   as a build step so the build fails if the branch is not green. For non-server
   repos, the Dockerfile should bring up a development environment and run
   `make check`. For server repos, `make check` should run as an early build
-  stage before the final image is assembled.
+  stage before the final image is assembled. 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 so the bootstrap
+  layer stays cached until dependencies change.
 
 - **Dockerfiles must use a separate lint stage for fail-fast feedback.** Go
   repos use a multistage build where linting runs in an independent stage based
@@ -127,8 +167,9 @@ style conventions are in separate documents:
       artifacts or heavier dependencies.
 
 - Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
-  runs `docker build .` on push. Since the Dockerfile already runs `make check`,
+  runs `script/cibuild` (which runs `docker build .`) on push. Since the
-  a successful build implies all checks pass.
+  Dockerfile already runs `make check`, a successful build implies all checks
+  pass.
 
 - Use platform-standard formatters: `black` for Python, `prettier` for
   JS/CSS/Markdown/HTML, `go fmt` for Go. Always use default configuration with
@@ -136,9 +177,11 @@ style conventions are in separate documents:
   Markdown (hard-wrap at 80 columns). Documentation and writing repos (Markdown,
   HTML, CSS) should also have `.prettierrc` and `.prettierignore`.
 
-- Pre-commit hook: `make check` if local testing is possible, otherwise
+- Pre-commit hook: runs `script/precommit`, which calls `script/check`. If local
-  `make lint && make fmt-check`. The Makefile should provide a `make hooks`
+  testing is not possible in the repo, `script/precommit` may skip `script/test`
-  target to install the pre-commit hook.
+  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
@@ -297,6 +340,10 @@ style conventions are in separate documents:
       "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
@@ -351,6 +398,9 @@ style conventions are in separate documents:
     - `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`

TODO.md

@@ -0,0 +1,47 @@
+# Workflow
+
+* branch (from `main`)
+* do the work in Next Step
+* move Next Step to the top of Completed Steps
+* move the top item of Future Steps into Next Step
+* commit (`TODO.md` changes in the same commit as the work)
+* merge to `main` if the branch is not protected, otherwise open a PR
+* push
+
+# Status
+
+pre-1.0
+
+# Next Step
+
+Bring the repo into policy compliance in one commit: add .gitignore,
+.dockerignore, .editorconfig, and .golangci.yml. Verify `make check` stays
+green with the new lint config.
+
+# Completed Steps
+
+- 2026-08-07: Added canonical `.golangci.yml`; pinned golangci-lint
+  v2.12.2 in the `Makefile` `deps` target (v2 module path, replacing
+  `@latest` on the old v1 path); fixed all lint issues surfaced by the
+  strict config across `cmd/bsdaily` and `internal/bsdaily`.
+- 2026-07-07 Adopted scripts-to-rule-them-all: `script/` entrypoints,
+  Makefile shims, README Entrypoints section
+- 2026-06-28: Fixed errcheck lint failures; added compilation smoke test;
+  tidied go.mod.
+- 2026-06-28: Added repo scaffolding: README, LICENSE, Makefile,
+  Dockerfile, REPO_POLICIES.md, and Gitea CI.
+- 2026-02-12: Fixed SQLite database locking by removing parallel
+  processing; fixed Linux build via golang.org/x/sys/unix Fadvise.
+- 2026-02-12: Optimized file copy for large databases; moved temp
+  directory to NVMe scratch storage.
+- 2026-02-11: Added date range support.
+- 2026-02-09: Initial implementation: single-day extraction, specific-date
+  targeting, faster pruning of throwaway database copies.
+
+# Future Steps
+
+- Add .gitignore, .dockerignore, .editorconfig, .golangci.yml (the Next
+  Step).
+- Expand tests beyond the compilation smoke test: unit tests for the
+  extraction, verification, and atomic-publish paths.
+- Cut a first SemVer release once compliance and test coverage land.

cmd/bsdaily/main.go

@@ -1,6 +1,9 @@
+// Package main implements bsdaily, a tool that extracts a single day's
+// data from the latest daily snapshot.
 package main
 
 import (
+	"errors"
 	"fmt"
 	"log/slog"
 	"os"
@@ -10,75 +13,110 @@ import (
 	"github.com/spf13/cobra"
 )
 
+var (
+	errDateExclusive  = errors.New("--date and --from/--to are mutually exclusive")
+	errFromRequiresTo = errors.New("--from requires --to")
+	errToRequiresFrom = errors.New("--to requires --from")
+	errFromAfterTo    = errors.New("--from is after --to")
+)
+
+func parseTargetDates(dateFlag, fromFlag, toFlag string) ([]time.Time, error) {
+	hasDate := dateFlag != ""
+	hasFrom := fromFlag != ""
+	hasTo := toFlag != ""
+
+	// Validate mutual exclusivity
+	if hasDate && (hasFrom || hasTo) {
+		return nil, errDateExclusive
+	}
+
+	if hasFrom != hasTo {
+		if hasFrom {
+			return nil, errFromRequiresTo
+		}
+
+		return nil, errToRequiresFrom
+	}
+
+	if hasDate {
+		t, err := time.Parse("2006-01-02", dateFlag)
+		if err != nil {
+			return nil, fmt.Errorf(
+				"invalid --date %q (expected YYYY-MM-DD): %w", dateFlag, err)
+		}
+
+		return []time.Time{t}, nil
+	}
+
+	if !hasFrom {
+		// nil → Run() defaults to snapshot date minus one
+		return nil, nil
+	}
+
+	from, err := time.Parse("2006-01-02", fromFlag)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"invalid --from %q (expected YYYY-MM-DD): %w", fromFlag, err)
+	}
+
+	to, err := time.Parse("2006-01-02", toFlag)
+	if err != nil {
+		return nil, fmt.Errorf(
+			"invalid --to %q (expected YYYY-MM-DD): %w", toFlag, err)
+	}
+
+	if from.After(to) {
+		return nil, fmt.Errorf(
+			"%w (--from %s, --to %s)", errFromAfterTo, fromFlag, toFlag)
+	}
+
+	var targetDates []time.Time
+
+	for d := from; !d.After(to); d = d.AddDate(0, 0, 1) {
+		targetDates = append(targetDates, d)
+	}
+
+	return targetDates, nil
+}
+
 func main() {
 	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
 		Level: slog.LevelInfo,
 	}))
 	slog.SetDefault(logger)
 
-	var dateFlag string
+	var dateFlag, fromFlag, toFlag string
-	var fromFlag string
-	var toFlag string
 
 	rootCmd := &cobra.Command{
 		Use:          "bsdaily",
 		Short:        "Extract a single day's data from the latest daily snapshot",
 		SilenceUsage: true,
-		RunE: func(cmd *cobra.Command, args []string) error {
+		RunE: func(_ *cobra.Command, _ []string) error {
-			hasDate := dateFlag != ""
+			targetDates, err := parseTargetDates(dateFlag, fromFlag, toFlag)
-			hasFrom := fromFlag != ""
+			if err != nil {
-			hasTo := toFlag != ""
-
-			// Validate mutual exclusivity
-			if hasDate && (hasFrom || hasTo) {
-				return fmt.Errorf("--date and --from/--to are mutually exclusive")
-			}
-			if hasFrom != hasTo {
-				if hasFrom {
-					return fmt.Errorf("--from requires --to")
-				}
-				return fmt.Errorf("--to requires --from")
-			}
-
-			var targetDates []time.Time
-
-			if hasDate {
-				t, err := time.Parse("2006-01-02", dateFlag)
-				if err != nil {
-					return fmt.Errorf("invalid --date %q (expected YYYY-MM-DD): %w", dateFlag, err)
-				}
-				targetDates = []time.Time{t}
-			} else if hasFrom {
-				from, err := time.Parse("2006-01-02", fromFlag)
-				if err != nil {
-					return fmt.Errorf("invalid --from %q (expected YYYY-MM-DD): %w", fromFlag, err)
-				}
-				to, err := time.Parse("2006-01-02", toFlag)
-				if err != nil {
-					return fmt.Errorf("invalid --to %q (expected YYYY-MM-DD): %w", toFlag, err)
-				}
-				if from.After(to) {
-					return fmt.Errorf("--from %s is after --to %s", fromFlag, toFlag)
-				}
-				for d := from; !d.After(to); d = d.AddDate(0, 0, 1) {
-					targetDates = append(targetDates, d)
-				}
-			}
-			// else: targetDates remains nil → Run() defaults to snapshot date minus one
-
-			if err := bsdaily.Run(targetDates); err != nil {
 				return err
 			}
+
+			err = bsdaily.Run(targetDates)
+			if err != nil {
+				return err
+			}
+
 			slog.Info("completed successfully")
+
 			return nil
 		},
 	}
 
-	rootCmd.Flags().StringVarP(&dateFlag, "date", "d", "", "target date to extract (YYYY-MM-DD); defaults to snapshot date minus one day")
+	rootCmd.Flags().StringVarP(&dateFlag, "date", "d", "",
-	rootCmd.Flags().StringVar(&fromFlag, "from", "", "start of date range to extract (YYYY-MM-DD, inclusive); use with --to")
+		"target date to extract (YYYY-MM-DD); defaults to snapshot date minus one")
-	rootCmd.Flags().StringVar(&toFlag, "to", "", "end of date range to extract (YYYY-MM-DD, inclusive); use with --from")
+	rootCmd.Flags().StringVar(&fromFlag, "from", "",
+		"start of date range to extract (YYYY-MM-DD, inclusive); use with --to")
+	rootCmd.Flags().StringVar(&toFlag, "to", "",
+		"end of date range to extract (YYYY-MM-DD, inclusive); use with --from")
 
-	if err := rootCmd.Execute(); err != nil {
+	err := rootCmd.Execute()
+	if err != nil {
 		os.Exit(1)
 	}
 }

internal/bsdaily/bsdaily_test.go

@@ -1,21 +1,32 @@
-package bsdaily
+package bsdaily_test
 
-import "testing"
+import (
+	"testing"
+
+	"git.eeqj.de/sneak/bsdaily/internal/bsdaily"
+)
 
 // TestCompiles is a minimal smoke test that references the package's exported
 // surface so that `go test` fails if the package stops compiling. It does not
 // touch the filesystem or any of the hard-coded production paths.
 func TestCompiles(t *testing.T) {
-	if DBFilename == "" || WALFilename == "" || SHMFilename == "" {
+	t.Parallel()
+
+	if bsdaily.DBFilename == "" || bsdaily.WALFilename == "" ||
+		bsdaily.SHMFilename == "" {
 		t.Fatal("expected database filename constants to be set")
 	}
-	if SnapshotBase == "" || TmpBase == "" || DailiesBase == "" {
+
+	if bsdaily.SnapshotBase == "" || bsdaily.TmpBase == "" ||
+		bsdaily.DailiesBase == "" {
 		t.Fatal("expected base path constants to be set")
 	}
-	if MinTmpFreeBytes == 0 || MinDailiesFreeBytes == 0 {
+
+	if bsdaily.MinTmpFreeBytes == 0 || bsdaily.MinDailiesFreeBytes == 0 {
 		t.Fatal("expected free-space thresholds to be set")
 	}
-	if ErrNoPosts == nil {
+
+	if bsdaily.ErrNoPosts == nil {
 		t.Fatal("expected ErrNoPosts sentinel to be set")
 	}
 }

internal/bsdaily/config.go

@@ -1,7 +1,11 @@
+// Package bsdaily extracts single-day compressed SQL dumps from the
+// latest daily ZFS snapshot of the firehose database.
 package bsdaily
 
 import "regexp"
 
+// Filesystem locations and tuning constants for the extraction
+// pipeline.
 const (
 	SnapshotBase = "/srv/berlin.sneak.fs.blueskyarchive/.zfs/snapshot"
 	TmpBase      = "/srv/storage/tmp"
@@ -27,4 +31,5 @@ const (
 	verificationHeadLines = 20
 )
 
-var snapshotPattern = regexp.MustCompile(`^zfs-auto-snap_daily-(\d{4}-\d{2}-\d{2})-\d{4}$`)
+var snapshotPattern = regexp.MustCompile(
+	`^zfs-auto-snap_daily-(\d{4}-\d{2}-\d{2})-\d{4}$`)

internal/bsdaily/copy.go

@@ -1,27 +1,42 @@
 package bsdaily
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"log/slog"
 	"os"
+	"path/filepath"
 	"time"
 )
 
 const (
-	copyBufferSize = 256 * 1024 * 1024 // 256MB buffer for large file copies from fast storage
+	// 256MB buffer for large file copies from fast storage
+	copyBufferSize = 256 * 1024 * 1024
+	oneMB          = 1024 * 1024
 	oneGB          = 1024 * 1024 * 1024
 )
 
+var errShortCopy = errors.New("short copy")
+
+// CopyFile copies src to dst using a large buffer, pre-allocating the
+// destination and fsyncing it before returning.
 func CopyFile(src, dst string) (err error) {
 	startTime := time.Now()
+
 	slog.Info("copying file", "src", src, "dst", dst)
 
-	srcFile, err := os.Open(src)
+	srcFile, err := os.Open(filepath.Clean(src))
 	if err != nil {
 		return fmt.Errorf("opening source %s: %w", src, err)
 	}
-	defer srcFile.Close()
+
+	defer func() {
+		cerr := srcFile.Close()
+		if cerr != nil {
+			slog.Warn("failed to close source file", "src", src, "error", cerr)
+		}
+	}()
 
 	srcInfo, err := srcFile.Stat()
 	if err != nil {
@@ -33,40 +48,48 @@ func CopyFile(src, dst string) (err error) {
 		applyFileAdvice(srcFile, srcInfo.Size())
 	}
 
-	dstFile, err := os.Create(dst)
+	dstFile, err := os.Create(filepath.Clean(dst))
 	if err != nil {
 		return fmt.Errorf("creating destination %s: %w", dst, err)
 	}
+
 	defer func() {
-		if cerr := dstFile.Close(); cerr != nil && err == nil {
+		cerr := dstFile.Close()
+		if cerr != nil && err == nil {
 			err = fmt.Errorf("closing destination %s: %w", dst, cerr)
 		}
 	}()
 
 	// Pre-allocate space for the destination file to avoid fragmentation
-	if err := dstFile.Truncate(srcInfo.Size()); err != nil {
+	terr := dstFile.Truncate(srcInfo.Size())
-		slog.Warn("failed to pre-allocate destination file", "error", err)
+	if terr != nil {
+		slog.Warn("failed to pre-allocate destination file", "error", terr)
 	}
 
 	// Use a much larger buffer for NVMe-speed copies
 	buf := make([]byte, copyBufferSize)
+
 	written, err := io.CopyBuffer(dstFile, srcFile, buf)
 	if err != nil {
 		return fmt.Errorf("copying data: %w", err)
 	}
 
 	if written != srcInfo.Size() {
-		return fmt.Errorf("short copy: wrote %d bytes, expected %d", written, srcInfo.Size())
+		return fmt.Errorf("%w: wrote %d bytes, expected %d",
+			errShortCopy, written, srcInfo.Size())
 	}
 
-	if err := dstFile.Sync(); err != nil {
+	err = dstFile.Sync()
+	if err != nil {
 		return fmt.Errorf("syncing destination %s: %w", dst, err)
 	}
 
 	elapsed := time.Since(startTime)
-	throughputMBps := float64(written) / elapsed.Seconds() / (1024 * 1024)
+	throughputMBps := float64(written) / elapsed.Seconds() / oneMB
+
 	slog.Info("file copied", "dst", dst, "bytes", written,
 		"elapsed", elapsed.Round(time.Millisecond),
 		"throughput_mbps", fmt.Sprintf("%.1f", throughputMBps))
+
 	return nil
 }

internal/bsdaily/copy_linux.go

@@ -3,14 +3,15 @@
 package bsdaily
 
 import (
-	"golang.org/x/sys/unix"
 	"os"
+
+	"golang.org/x/sys/unix"
 )
 
+// applyFileAdvice hints to the kernel that file will be read
+// sequentially and should be prefetched into the page cache.
 func applyFileAdvice(file *os.File, size int64) {
 	fd := int(file.Fd())
-	// POSIX_FADV_SEQUENTIAL = 2
+	_ = unix.Fadvise(fd, 0, size, unix.FADV_SEQUENTIAL)
-	_ = unix.Fadvise(fd, 0, size, 2)
+	_ = unix.Fadvise(fd, 0, size, unix.FADV_WILLNEED)
-	// POSIX_FADV_WILLNEED = 3 - prefetch file into cache
-	_ = unix.Fadvise(fd, 0, size, 3)
 }

internal/bsdaily/disk.go

@@ -1,26 +1,42 @@
 package bsdaily
 
 import (
+	"errors"
 	"fmt"
 	"log/slog"
 
 	"golang.org/x/sys/unix"
 )
 
+var errInsufficientSpace = errors.New("insufficient disk space")
+
+// CheckFreeSpace returns an error when the filesystem containing path
+// has fewer than minBytes bytes available.
 func CheckFreeSpace(path string, minBytes uint64, label string) error {
 	var stat unix.Statfs_t
-	if err := unix.Statfs(path, &stat); err != nil {
+
+	err := unix.Statfs(path, &stat)
+	if err != nil {
 		return fmt.Errorf("statfs %s (%s): %w", path, label, err)
 	}
-	free := uint64(stat.Bavail) * uint64(stat.Bsize)
+
+	var blockSize uint64
+	if stat.Bsize > 0 {
+		blockSize = uint64(stat.Bsize)
+	}
+
+	free := stat.Bavail * blockSize
 	freeGB := float64(free) / float64(bytesPerGB)
 	minGB := float64(minBytes) / float64(bytesPerGB)
+
 	slog.Info("disk space check", "label", label, "path", path,
 		"free_gb", fmt.Sprintf("%.1f", freeGB),
 		"required_gb", fmt.Sprintf("%.1f", minGB))
+
 	if free < minBytes {
-		return fmt.Errorf("insufficient disk space on %s (%s): %.1f GB free, need %.1f GB",
+		return fmt.Errorf("%w on %s (%s): %.1f GB free, need %.1f GB",
-			path, label, freeGB, minGB)
+			errInsufficientSpace, path, label, freeGB, minGB)
 	}
+
 	return nil
 }

internal/bsdaily/dump.go

@@ -1,6 +1,8 @@
 package bsdaily
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"log/slog"
 	"os"
@@ -9,61 +11,43 @@ import (
 	"strings"
 )
 
+var errEmptyOutput = errors.New("compressed output is empty")
+
+// DumpAndCompress dumps the SQLite database at dbPath to SQL text via
+// sqlite3 and compresses it with zstdmt into outputPath.
 func DumpAndCompress(dbPath, outputPath string) (err error) {
 	for _, tool := range []string{"sqlite3", "zstdmt"} {
-		if _, err := exec.LookPath(tool); err != nil {
+		_, lerr := exec.LookPath(tool)
-			return fmt.Errorf("required tool %q not found in PATH: %w", tool, err)
+		if lerr != nil {
+			return fmt.Errorf("required tool %q not found in PATH: %w", tool, lerr)
 		}
 	}
 
-	if err := CheckFreeSpace(filepath.Dir(outputPath), MinDailiesFreeBytes, "dailiesBase (pre-dump)"); err != nil {
+	err = CheckFreeSpace(
+		filepath.Dir(outputPath), MinDailiesFreeBytes, "dailiesBase (pre-dump)")
+	if err != nil {
 		return err
 	}
 
-	outFile, err := os.Create(outputPath)
+	outFile, err := os.Create(filepath.Clean(outputPath))
 	if err != nil {
 		return fmt.Errorf("creating output file: %w", err)
 	}
+
 	defer func() {
-		if cerr := outFile.Close(); cerr != nil && err == nil {
+		cerr := outFile.Close()
+		if cerr != nil && err == nil {
 			err = fmt.Errorf("closing output: %w", cerr)
 		}
 	}()
 
-	// Dump all tables but use INSERT OR IGNORE for mergeable imports
+	err = runDumpPipeline(context.Background(), dbPath, outFile)
-	// This preserves all data while allowing multiple dumps to be merged
-	// Users should import with: zstdcat *.sql.zst | sed 's/INSERT INTO/INSERT OR IGNORE INTO/g' | sqlite3 merged.db
-	dumpCmd := exec.Command("sqlite3", dbPath, ".dump")
-	zstdCmd := exec.Command("zstdmt", fmt.Sprintf("-%d", zstdCompressionLevel))
-
-	pipe, err := dumpCmd.StdoutPipe()
 	if err != nil {
-		return fmt.Errorf("creating dump stdout pipe: %w", err)
+		return err
-	}
-	zstdCmd.Stdin = pipe
-	zstdCmd.Stdout = outFile
-
-	var dumpStderr, zstdStderr strings.Builder
-	dumpCmd.Stderr = &dumpStderr
-	zstdCmd.Stderr = &zstdStderr
-
-	slog.Info("starting sqlite3 dump and zstdmt compression")
-
-	if err := zstdCmd.Start(); err != nil {
-		return fmt.Errorf("starting zstdmt: %w", err)
-	}
-	if err := dumpCmd.Start(); err != nil {
-		return fmt.Errorf("starting sqlite3 dump: %w", err)
 	}
 
-	if err := dumpCmd.Wait(); err != nil {
+	err = outFile.Sync()
-		return fmt.Errorf("sqlite3 dump failed: %w; stderr: %s", err, dumpStderr.String())
+	if err != nil {
-	}
-	if err := zstdCmd.Wait(); err != nil {
-		return fmt.Errorf("zstdmt failed: %w; stderr: %s", err, zstdStderr.String())
-	}
-
-	if err := outFile.Sync(); err != nil {
 		return fmt.Errorf("syncing output: %w", err)
 	}
 
@@ -71,12 +55,69 @@ func DumpAndCompress(dbPath, outputPath string) (err error) {
 	if err != nil {
 		return fmt.Errorf("stat output: %w", err)
 	}
+
 	const bytesPerMB = 1024 * 1024
+
 	slog.Info("compressed output written", "path", outputPath,
 		"size_bytes", info.Size(), "size_mb", info.Size()/bytesPerMB)
 
 	if info.Size() == 0 {
-		return fmt.Errorf("compressed output is empty")
+		return errEmptyOutput
+	}
+
+	return nil
+}
+
+// runDumpPipeline streams a sqlite3 .dump of dbPath through zstdmt
+// into outFile.
+func runDumpPipeline(ctx context.Context, dbPath string, outFile *os.File) error {
+	// Dump all tables but use INSERT OR IGNORE for mergeable imports.
+	// This preserves all data while allowing multiple dumps to be
+	// merged. Users should import with:
+	//   zstdcat *.sql.zst \
+	//     | sed 's/INSERT INTO/INSERT OR IGNORE INTO/g' \
+	//     | sqlite3 merged.db
+	zstdArg := fmt.Sprintf("-%d", zstdCompressionLevel)
+
+	//nolint:gosec // sqlite3 with internally constructed path
+	dumpCmd := exec.CommandContext(ctx, "sqlite3", dbPath, ".dump")
+	//nolint:gosec // zstdmt with fixed compression argument
+	zstdCmd := exec.CommandContext(ctx, "zstdmt", zstdArg)
+
+	pipe, err := dumpCmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("creating dump stdout pipe: %w", err)
+	}
+
+	zstdCmd.Stdin = pipe
+	zstdCmd.Stdout = outFile
+
+	var dumpStderr, zstdStderr strings.Builder
+
+	dumpCmd.Stderr = &dumpStderr
+	zstdCmd.Stderr = &zstdStderr
+
+	slog.Info("starting sqlite3 dump and zstdmt compression")
+
+	err = zstdCmd.Start()
+	if err != nil {
+		return fmt.Errorf("starting zstdmt: %w", err)
+	}
+
+	err = dumpCmd.Start()
+	if err != nil {
+		return fmt.Errorf("starting sqlite3 dump: %w", err)
+	}
+
+	err = dumpCmd.Wait()
+	if err != nil {
+		return fmt.Errorf("sqlite3 dump failed: %w; stderr: %s",
+			err, dumpStderr.String())
+	}
+
+	err = zstdCmd.Wait()
+	if err != nil {
+		return fmt.Errorf("zstdmt failed: %w; stderr: %s", err, zstdStderr.String())
 	}
 
 	return nil

internal/bsdaily/extract.go

@@ -1,171 +1,315 @@
 package bsdaily
 
 import (
+	"context"
 	"database/sql"
 	"errors"
 	"fmt"
 	"log/slog"
 	"time"
 
+	// Register the pure-Go sqlite driver with database/sql.
 	_ "modernc.org/sqlite"
 )
 
+// ErrNoPosts is returned when the source database contains no posts
+// for the target day.
 var ErrNoPosts = errors.New("no posts found for target day")
 
+var errPostCountMismatch = errors.New("post count mismatch")
+
 // ExtractDay opens a new empty database at dstDBPath, attaches srcDBPath,
 // and copies only the target day's data into it. This is much faster than
 // pruning a full copy because it only reads/writes the small slice of data
 // being kept.
 func ExtractDay(srcDBPath, dstDBPath string, targetDay time.Time) error {
+	ctx := context.Background()
 	dayStart := targetDay.Format("2006-01-02") + "T00:00:00"
 	dayEnd := targetDay.AddDate(0, 0, 1).Format("2006-01-02") + "T00:00:00"
 
 	slog.Info("extracting day", "from", dayStart, "until", dayEnd)
 
-	// Maximum performance pragmas - we don't care about crash safety for temp files
+	// Maximum performance pragmas - we don't care about crash safety
-	// Use WAL mode for the source attachment to avoid locking issues
+	// for temp files. Use WAL mode for the source attachment to avoid
-	pragmas := fmt.Sprintf("?_pragma=journal_mode(WAL)&_pragma=synchronous(OFF)&_pragma=cache_size(%d)&_pragma=foreign_keys(OFF)&_pragma=temp_store(MEMORY)&_pragma=busy_timeout(5000)", sqliteCacheSizeKB)
+	// locking issues.
+	pragmas := fmt.Sprintf(
+		"?_pragma=journal_mode(WAL)&_pragma=synchronous(OFF)"+
+			"&_pragma=cache_size(%d)&_pragma=foreign_keys(OFF)"+
+			"&_pragma=temp_store(MEMORY)&_pragma=busy_timeout(5000)",
+		sqliteCacheSizeKB)
+
 	db, err := sql.Open("sqlite", dstDBPath+pragmas)
 	if err != nil {
 		return fmt.Errorf("opening destination database: %w", err)
 	}
-	defer db.Close()
 
-	// Attach source database
-	if _, err := db.Exec("ATTACH DATABASE ? AS src", srcDBPath); err != nil {
-		return fmt.Errorf("attaching source database: %w", err)
-	}
-
-	// Copy table DDL from source
-	slog.Info("copying table DDL from source")
-	rows, err := db.Query("SELECT sql FROM src.sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%' ORDER BY name")
-	if err != nil {
-		return fmt.Errorf("reading source schema: %w", err)
-	}
-	defer rows.Close()
-
-	var ddlStatements []string
-	for rows.Next() {
-		var ddl string
-		if err := rows.Scan(&ddl); err != nil {
-			return fmt.Errorf("scanning DDL: %w", err)
-		}
-		ddlStatements = append(ddlStatements, ddl)
-	}
-	if err := rows.Err(); err != nil {
-		return fmt.Errorf("iterating DDL rows: %w", err)
-	}
-
-	for _, ddl := range ddlStatements {
-		if _, err := db.Exec(ddl); err != nil {
-			return fmt.Errorf("creating table: %w\nDDL: %s", err, ddl)
-		}
-	}
-
-	// Begin transaction for bulk inserts
-	tx, err := db.Begin()
-	if err != nil {
-		return fmt.Errorf("beginning transaction: %w", err)
-	}
 	defer func() {
-		if err != nil {
+		cerr := db.Close()
-			tx.Rollback()
+		if cerr != nil {
+			slog.Warn("failed to close destination database",
+				"path", dstDBPath, "error", cerr)
 		}
 	}()
 
-	// Insert target day's data
+	// Attach source database
-	slog.Info("inserting posts for target day")
+	_, err = db.ExecContext(ctx, "ATTACH DATABASE ? AS src", srcDBPath)
-	result, err := tx.Exec("INSERT INTO posts SELECT * FROM src.posts WHERE timestamp >= ? AND timestamp < ?", dayStart, dayEnd)
 	if err != nil {
-		return fmt.Errorf("inserting posts: %w", err)
+		return fmt.Errorf("attaching source database: %w", err)
-	}
-	postCount, _ := result.RowsAffected()
-	slog.Info("inserted posts", "count", postCount)
-
-	if postCount == 0 {
-		return fmt.Errorf("%w %s - aborting to avoid producing empty output",
-			ErrNoPosts, targetDay.Format("2006-01-02"))
 	}
 
-	slog.Info("inserting junction and lookup tables")
+	err = copySchema(ctx, db)
-	if _, err := tx.Exec("INSERT INTO posts_hashtags SELECT * FROM src.posts_hashtags WHERE post_id IN (SELECT id FROM posts)"); err != nil {
-		return fmt.Errorf("inserting posts_hashtags: %w", err)
-	}
-
-	if _, err := tx.Exec("INSERT INTO posts_urls SELECT * FROM src.posts_urls WHERE post_id IN (SELECT id FROM posts)"); err != nil {
-		return fmt.Errorf("inserting posts_urls: %w", err)
-	}
-
-	if _, err := tx.Exec("INSERT INTO hashtags SELECT * FROM src.hashtags WHERE id IN (SELECT hashtag_id FROM posts_hashtags)"); err != nil {
-		return fmt.Errorf("inserting hashtags: %w", err)
-	}
-
-	if _, err := tx.Exec("INSERT INTO urls SELECT * FROM src.urls WHERE id IN (SELECT url_id FROM posts_urls)"); err != nil {
-		return fmt.Errorf("inserting urls: %w", err)
-	}
-
-	if _, err := tx.Exec("INSERT INTO users SELECT * FROM src.users WHERE did IN (SELECT user_did FROM posts)"); err != nil {
-		return fmt.Errorf("inserting users: %w", err)
-	}
-
-	// Check if media table exists in source and copy if present
-	var mediaTableExists int
-	if err := tx.QueryRow("SELECT COUNT(*) FROM src.sqlite_master WHERE type='table' AND name='media'").Scan(&mediaTableExists); err != nil {
-		slog.Warn("checking for media table", "error", err)
-	} else if mediaTableExists > 0 {
-		slog.Info("inserting media entries")
-		// Get post blob_cids for this day's posts
-		if _, err := tx.Exec("INSERT INTO media SELECT * FROM src.media WHERE content_hash IN (SELECT blob_cids FROM posts WHERE blob_cids IS NOT NULL)"); err != nil {
-			slog.Warn("inserting media (may not have matching entries)", "error", err)
-		}
-	}
-
-	// Commit the transaction before any further database operations
-	if err := tx.Commit(); err != nil {
-		return fmt.Errorf("committing transaction: %w", err)
-	}
-	tx = nil // Clear tx to ensure defer doesn't try to rollback
-
-	// Create indexes after bulk insert for speed
-	slog.Info("creating indexes")
-	idxRows, err := db.Query("SELECT sql FROM src.sqlite_master WHERE type='index' AND name NOT LIKE 'sqlite_%' AND sql IS NOT NULL ORDER BY name")
 	if err != nil {
-		return fmt.Errorf("reading source indexes: %w", err)
+		return err
-	}
-	defer idxRows.Close()
-
-	var idxStatements []string
-	for idxRows.Next() {
-		var idxSQL string
-		if err := idxRows.Scan(&idxSQL); err != nil {
-			return fmt.Errorf("scanning index DDL: %w", err)
-		}
-		idxStatements = append(idxStatements, idxSQL)
-	}
-	if err := idxRows.Err(); err != nil {
-		return fmt.Errorf("iterating index rows: %w", err)
 	}
 
-	for _, idxSQL := range idxStatements {
+	postCount, err := insertDayData(ctx, db, targetDay, dayStart, dayEnd)
-		if _, err := db.Exec(idxSQL); err != nil {
+	if err != nil {
-			return fmt.Errorf("creating index: %w\nDDL: %s", err, idxSQL)
+		return err
-		}
+	}
+
+	err = createIndexes(ctx, db)
+	if err != nil {
+		return err
 	}
 
 	// Detach source
-	if _, err := db.Exec("DETACH DATABASE src"); err != nil {
+	_, err = db.ExecContext(ctx, "DETACH DATABASE src")
+	if err != nil {
 		return fmt.Errorf("detaching source database: %w", err)
 	}
 
 	// Verify post count
 	var verifyCount int64
-	if err := db.QueryRow("SELECT COUNT(*) FROM posts").Scan(&verifyCount); err != nil {
+
+	err = db.QueryRowContext(ctx, "SELECT COUNT(*) FROM posts").Scan(&verifyCount)
+	if err != nil {
 		return fmt.Errorf("verifying post count: %w", err)
 	}
+
 	if verifyCount != postCount {
-		return fmt.Errorf("post count mismatch: inserted %d but found %d", postCount, verifyCount)
+		return fmt.Errorf("%w: inserted %d but found %d",
+			errPostCountMismatch, postCount, verifyCount)
 	}
+
 	slog.Info("extraction complete", "posts", verifyCount)
 
 	return nil
 }
+
+// collectSQL runs a query returning a single text column and collects
+// the non-NULL results in order.
+func collectSQL(ctx context.Context, db *sql.DB, query string) ([]string, error) {
+	rows, err := db.QueryContext(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+
+	defer func() {
+		cerr := rows.Close()
+		if cerr != nil {
+			slog.Warn("failed to close rows", "error", cerr)
+		}
+	}()
+
+	var statements []string
+
+	for rows.Next() {
+		var stmt string
+
+		err = rows.Scan(&stmt)
+		if err != nil {
+			return nil, fmt.Errorf("scanning row: %w", err)
+		}
+
+		statements = append(statements, stmt)
+	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, fmt.Errorf("iterating rows: %w", err)
+	}
+
+	return statements, nil
+}
+
+// copySchema copies the table DDL from the attached src database into
+// the destination database.
+func copySchema(ctx context.Context, db *sql.DB) error {
+	slog.Info("copying table DDL from source")
+
+	ddlStatements, err := collectSQL(ctx, db,
+		"SELECT sql FROM src.sqlite_master WHERE type='table' "+
+			"AND name NOT LIKE 'sqlite_%' ORDER BY name")
+	if err != nil {
+		return fmt.Errorf("reading source schema: %w", err)
+	}
+
+	for _, ddl := range ddlStatements {
+		_, err = db.ExecContext(ctx, ddl)
+		if err != nil {
+			return fmt.Errorf("creating table: %w\nDDL: %s", err, ddl)
+		}
+	}
+
+	return nil
+}
+
+// insertLookupTables copies the junction and lookup rows related to
+// the already-inserted posts from the attached src database.
+//
+//nolint:unqueryvet // full-row copies; schema is defined by source DB
+func insertLookupTables(ctx context.Context, tx *sql.Tx) error {
+	inserts := []struct {
+		label string
+		query string
+	}{
+		{"posts_hashtags", "INSERT INTO posts_hashtags " +
+			"SELECT * FROM src.posts_hashtags " +
+			"WHERE post_id IN (SELECT id FROM posts)"},
+		{"posts_urls", "INSERT INTO posts_urls " +
+			"SELECT * FROM src.posts_urls " +
+			"WHERE post_id IN (SELECT id FROM posts)"},
+		{"hashtags", "INSERT INTO hashtags " +
+			"SELECT * FROM src.hashtags " +
+			"WHERE id IN (SELECT hashtag_id FROM posts_hashtags)"},
+		{"urls", "INSERT INTO urls " +
+			"SELECT * FROM src.urls " +
+			"WHERE id IN (SELECT url_id FROM posts_urls)"},
+		{"users", "INSERT INTO users " +
+			"SELECT * FROM src.users " +
+			"WHERE did IN (SELECT user_did FROM posts)"},
+	}
+
+	for _, ins := range inserts {
+		_, err := tx.ExecContext(ctx, ins.query)
+		if err != nil {
+			return fmt.Errorf("inserting %s: %w", ins.label, err)
+		}
+	}
+
+	return nil
+}
+
+// insertDayData copies the target day's posts and their related
+// junction and lookup rows from the attached src database inside a
+// single transaction. It returns the number of posts inserted.
+func insertDayData(
+	ctx context.Context,
+	db *sql.DB,
+	targetDay time.Time,
+	dayStart, dayEnd string,
+) (int64, error) {
+	// Begin transaction for bulk inserts
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return 0, fmt.Errorf("beginning transaction: %w", err)
+	}
+
+	committed := false
+
+	defer func() {
+		if committed {
+			return
+		}
+
+		rerr := tx.Rollback()
+		if rerr != nil && !errors.Is(rerr, sql.ErrTxDone) {
+			slog.Warn("failed to roll back transaction", "error", rerr)
+		}
+	}()
+
+	// Insert target day's data
+	slog.Info("inserting posts for target day")
+
+	//nolint:unqueryvet // full-row copy; schema is defined by source DB
+	result, err := tx.ExecContext(ctx,
+		"INSERT INTO posts SELECT * FROM src.posts "+
+			"WHERE timestamp >= ? AND timestamp < ?", dayStart, dayEnd)
+	if err != nil {
+		return 0, fmt.Errorf("inserting posts: %w", err)
+	}
+
+	postCount, _ := result.RowsAffected()
+
+	slog.Info("inserted posts", "count", postCount)
+
+	if postCount == 0 {
+		return 0, fmt.Errorf("%w %s - aborting to avoid producing empty output",
+			ErrNoPosts, targetDay.Format("2006-01-02"))
+	}
+
+	slog.Info("inserting junction and lookup tables")
+
+	err = insertLookupTables(ctx, tx)
+	if err != nil {
+		return 0, err
+	}
+
+	copyMediaTable(ctx, tx)
+
+	// Commit the transaction before any further database operations
+	err = tx.Commit()
+	if err != nil {
+		return 0, fmt.Errorf("committing transaction: %w", err)
+	}
+
+	committed = true
+
+	return postCount, nil
+}
+
+// copyMediaTable copies the media table when it exists in the source.
+// Failures are logged rather than fatal because the source may not
+// have a media table or matching entries.
+func copyMediaTable(ctx context.Context, tx *sql.Tx) {
+	// Check if media table exists in source and copy if present
+	var mediaTableExists int
+
+	err := tx.QueryRowContext(ctx,
+		"SELECT COUNT(*) FROM src.sqlite_master "+
+			"WHERE type='table' AND name='media'").Scan(&mediaTableExists)
+	if err != nil {
+		slog.Warn("checking for media table", "error", err)
+
+		return
+	}
+
+	if mediaTableExists == 0 {
+		return
+	}
+
+	slog.Info("inserting media entries")
+
+	// Get post blob_cids for this day's posts
+	//nolint:unqueryvet // full-row copy; schema is defined by source DB
+	_, err = tx.ExecContext(ctx,
+		"INSERT INTO media SELECT * FROM src.media "+
+			"WHERE content_hash IN "+
+			"(SELECT blob_cids FROM posts WHERE blob_cids IS NOT NULL)")
+	if err != nil {
+		slog.Warn("inserting media (may not have matching entries)", "error", err)
+	}
+}
+
+// createIndexes recreates the source database's indexes after the bulk
+// insert, which is faster than inserting into indexed tables.
+func createIndexes(ctx context.Context, db *sql.DB) error {
+	// Create indexes after bulk insert for speed
+	slog.Info("creating indexes")
+
+	idxStatements, err := collectSQL(ctx, db,
+		"SELECT sql FROM src.sqlite_master WHERE type='index' "+
+			"AND name NOT LIKE 'sqlite_%' AND sql IS NOT NULL ORDER BY name")
+	if err != nil {
+		return fmt.Errorf("reading source indexes: %w", err)
+	}
+
+	for _, idxSQL := range idxStatements {
+		_, err = db.ExecContext(ctx, idxSQL)
+		if err != nil {
+			return fmt.Errorf("creating index: %w\nDDL: %s", err, idxSQL)
+		}
+	}
+
+	return nil
+}

internal/bsdaily/run.go

@@ -9,12 +9,33 @@ import (
 	"time"
 )
 
+var errEmptySource = errors.New("source file is empty")
+
+// outputDirPerm is world-readable because the dailies tree is
+// published for download.
+const outputDirPerm = 0o755
+
+// cleanup removes a temporary file, logging a warning if removal fails so
+// that leaked scratch files are surfaced rather than silently ignored. A
+// missing file is not an error.
+func cleanup(path string) {
+	err := os.Remove(path)
+	if err != nil && !os.IsNotExist(err) {
+		slog.Warn("failed to remove temporary file", "path", path, "error", err)
+	}
+}
+
+// Run extracts each requested day from the latest daily snapshot into
+// a compressed SQL dump. When targetDates is empty it defaults to the
+// snapshot date minus one day.
 func Run(targetDates []time.Time) error {
 	snapshotDir, snapshotDate, err := FindLatestDailySnapshot()
 	if err != nil {
 		return fmt.Errorf("finding latest snapshot: %w", err)
 	}
-	slog.Info("found latest daily snapshot", "dir", snapshotDir, "snapshot_date", snapshotDate.Format("2006-01-02"))
+
+	slog.Info("found latest daily snapshot", "dir", snapshotDir,
+		"snapshot_date", snapshotDate.Format("2006-01-02"))
 
 	if len(targetDates) == 0 {
 		targetDates = []time.Time{snapshotDate.AddDate(0, 0, -1)}
@@ -25,10 +46,13 @@ func Run(targetDates []time.Time) error {
 		"last", targetDates[len(targetDates)-1].Format("2006-01-02"))
 
 	// Check disk space
-	if err := CheckFreeSpace(TmpBase, MinTmpFreeBytes, "tmpBase"); err != nil {
+	err = CheckFreeSpace(TmpBase, MinTmpFreeBytes, "tmpBase")
+	if err != nil {
 		return err
 	}
-	if err := CheckFreeSpace(DailiesBase, MinDailiesFreeBytes, "dailiesBase"); err != nil {
+
+	err = CheckFreeSpace(DailiesBase, MinDailiesFreeBytes, "dailiesBase")
+	if err != nil {
 		return err
 	}
 
@@ -37,15 +61,54 @@ func Run(targetDates []time.Time) error {
 	if err != nil {
 		return fmt.Errorf("creating temp directory in %s: %w", TmpBase, err)
 	}
+
 	slog.Info("created temp directory", "path", tmpDir)
+
 	defer func() {
 		slog.Info("cleaning up temp directory", "path", tmpDir)
-		if err := os.RemoveAll(tmpDir); err != nil {
+
-			slog.Error("failed to remove temp directory", "path", tmpDir, "error", err)
+		rerr := os.RemoveAll(tmpDir)
+		if rerr != nil {
+			slog.Error("failed to remove temp directory",
+				"path", tmpDir, "error", rerr)
 		}
 	}()
 
 	// Copy database files from snapshot to temp
+	dstDB, err := copySnapshotFiles(snapshotDir, tmpDir)
+	if err != nil {
+		return err
+	}
+
+	// Process each day completely before moving to the next. This
+	// ensures we don't have multiple SQLite operations competing for
+	// the same source database.
+	processed := 0
+	skipped := 0
+
+	for _, targetDay := range targetDates {
+		didProcess, perr := processDay(tmpDir, dstDB, targetDay)
+		if perr != nil {
+			return perr
+		}
+
+		if didProcess {
+			processed++
+		} else {
+			skipped++
+		}
+	}
+
+	slog.Info("run summary", "processed", processed,
+		"skipped", skipped, "total", len(targetDates))
+
+	return nil
+}
+
+// copySnapshotFiles copies the database, WAL, and (if present) SHM
+// files from the snapshot directory into tmpDir and returns the path
+// of the copied database.
+func copySnapshotFiles(snapshotDir, tmpDir string) (string, error) {
 	srcDB := filepath.Join(snapshotDir, DBFilename)
 	srcWAL := filepath.Join(snapshotDir, WALFilename)
 	srcSHM := filepath.Join(snapshotDir, SHMFilename)
@@ -56,100 +119,136 @@ func Run(targetDates []time.Time) error {
 	for _, f := range []string{srcDB, srcWAL} {
 		info, err := os.Stat(f)
 		if err != nil {
-			return fmt.Errorf("source file missing: %s: %w", f, err)
+			return "", fmt.Errorf("source file missing: %s: %w", f, err)
 		}
+
 		if info.Size() == 0 {
-			return fmt.Errorf("source file is empty: %s", f)
+			return "", fmt.Errorf("%w: %s", errEmptySource, f)
 		}
+
 		slog.Info("source file", "path", f, "size_bytes", info.Size())
 	}
 
-	if err := CopyFile(srcDB, dstDB); err != nil {
+	err := CopyFile(srcDB, dstDB)
-		return fmt.Errorf("copying database: %w", err)
+	if err != nil {
-	}
+		return "", fmt.Errorf("copying database: %w", err)
-	if err := CopyFile(srcWAL, dstWAL); err != nil {
-		return fmt.Errorf("copying WAL: %w", err)
-	}
-	if _, err := os.Stat(srcSHM); err == nil {
-		if err := CopyFile(srcSHM, dstSHM); err != nil {
-			return fmt.Errorf("copying SHM: %w", err)
-		}
 	}
 
-	// Process each day completely before moving to the next
+	err = CopyFile(srcWAL, dstWAL)
-	// This ensures we don't have multiple SQLite operations competing for the same source database
+	if err != nil {
-	processed := 0
+		return "", fmt.Errorf("copying WAL: %w", err)
-	skipped := 0
+	}
 
-	for _, targetDay := range targetDates {
+	_, err = os.Stat(srcSHM)
-		dayStr := targetDay.Format("2006-01-02")
+	if err == nil {
-		slog.Info("processing day", "date", dayStr)
+		err = CopyFile(srcSHM, dstSHM)
-
-		// Check if output already exists
-		outputDir := filepath.Join(DailiesBase, targetDay.Format("2006-01"))
-		outputFinal := filepath.Join(outputDir, dayStr+".sql.zst")
-		if _, err := os.Stat(outputFinal); err == nil {
-			slog.Info("output already exists, skipping", "path", outputFinal)
-			skipped++
-			continue
-		}
-
-		// Extract target day into a per-day database
-		extractedDB := filepath.Join(tmpDir, "extracted-"+dayStr+".db")
-		slog.Info("extracting target day", "src", dstDB, "dst", extractedDB)
-		if err := ExtractDay(dstDB, extractedDB, targetDay); err != nil {
-			if errors.Is(err, ErrNoPosts) {
-				slog.Warn("no posts found, skipping day", "date", dayStr)
-				os.Remove(extractedDB)
-				skipped++
-				continue
-			}
-			return fmt.Errorf("extracting day %s: %w", dayStr, err)
-		}
-
-		// Dump to SQL and compress
-		if err := os.MkdirAll(outputDir, 0755); err != nil {
-			os.Remove(extractedDB)
-			return fmt.Errorf("creating output directory %s: %w", outputDir, err)
-		}
-
-		outputTmp := filepath.Join(outputDir, "."+dayStr+".sql.zst.tmp")
-
-		slog.Info("dumping and compressing", "tmp_output", outputTmp)
-		if err := DumpAndCompress(extractedDB, outputTmp); err != nil {
-			os.Remove(outputTmp)
-			os.Remove(extractedDB)
-			return fmt.Errorf("dump and compress for %s: %w", dayStr, err)
-		}
-
-		slog.Info("verifying compressed output")
-		if err := VerifyOutput(outputTmp); err != nil {
-			os.Remove(outputTmp)
-			os.Remove(extractedDB)
-			return fmt.Errorf("verification failed for %s: %w", dayStr, err)
-		}
-
-		// Atomic rename to final path
-		slog.Info("renaming to final output", "from", outputTmp, "to", outputFinal)
-		if err := os.Rename(outputTmp, outputFinal); err != nil {
-			os.Remove(outputTmp)
-			os.Remove(extractedDB)
-			return fmt.Errorf("atomic rename for %s: %w", dayStr, err)
-		}
-
-		info, err := os.Stat(outputFinal)
 		if err != nil {
-			os.Remove(extractedDB)
+			return "", fmt.Errorf("copying SHM: %w", err)
-			return fmt.Errorf("stat final output: %w", err)
 		}
-		slog.Info("day completed", "date", dayStr, "path", outputFinal, "size_bytes", info.Size())
-
-		// Remove extracted DB to reclaim space immediately
-		os.Remove(extractedDB)
-		processed++
 	}
 
-	slog.Info("run summary", "processed", processed, "skipped", skipped, "total", len(targetDates))
+	return dstDB, nil
+}
+
+// processDay extracts, dumps, compresses, verifies, and publishes a
+// single day. It reports whether the day was processed; false means it
+// was skipped (already present or no posts).
+func processDay(tmpDir, dstDB string, targetDay time.Time) (bool, error) {
+	dayStr := targetDay.Format("2006-01-02")
+
+	slog.Info("processing day", "date", dayStr)
+
+	// Check if output already exists
+	outputDir := filepath.Join(DailiesBase, targetDay.Format("2006-01"))
+	outputFinal := filepath.Join(outputDir, dayStr+".sql.zst")
+
+	_, err := os.Stat(outputFinal)
+	if err == nil {
+		slog.Info("output already exists, skipping", "path", outputFinal)
+
+		return false, nil
+	}
+
+	// Extract target day into a per-day database
+	extractedDB := filepath.Join(tmpDir, "extracted-"+dayStr+".db")
+
+	slog.Info("extracting target day", "src", dstDB, "dst", extractedDB)
+
+	err = ExtractDay(dstDB, extractedDB, targetDay)
+	if err != nil {
+		if errors.Is(err, ErrNoPosts) {
+			slog.Warn("no posts found, skipping day", "date", dayStr)
+			cleanup(extractedDB)
+
+			return false, nil
+		}
+
+		return false, fmt.Errorf("extracting day %s: %w", dayStr, err)
+	}
+
+	// Dump to SQL and compress
+	err = os.MkdirAll(outputDir, outputDirPerm)
+	if err != nil {
+		cleanup(extractedDB)
+
+		return false, fmt.Errorf("creating output directory %s: %w", outputDir, err)
+	}
+
+	outputTmp := filepath.Join(outputDir, "."+dayStr+".sql.zst.tmp")
+
+	slog.Info("dumping and compressing", "tmp_output", outputTmp)
+
+	err = DumpAndCompress(extractedDB, outputTmp)
+	if err != nil {
+		cleanup(outputTmp)
+		cleanup(extractedDB)
+
+		return false, fmt.Errorf("dump and compress for %s: %w", dayStr, err)
+	}
+
+	slog.Info("verifying compressed output")
+
+	err = VerifyOutput(outputTmp)
+	if err != nil {
+		cleanup(outputTmp)
+		cleanup(extractedDB)
+
+		return false, fmt.Errorf("verification failed for %s: %w", dayStr, err)
+	}
+
+	err = publishOutput(outputTmp, outputFinal, dayStr)
+	if err != nil {
+		cleanup(extractedDB)
+
+		return false, err
+	}
+
+	// Remove extracted DB to reclaim space immediately
+	cleanup(extractedDB)
+
+	return true, nil
+}
+
+// publishOutput atomically renames the temporary output file to its
+// final path and logs the completed day.
+func publishOutput(outputTmp, outputFinal, dayStr string) error {
+	// Atomic rename to final path
+	slog.Info("renaming to final output", "from", outputTmp, "to", outputFinal)
+
+	err := os.Rename(outputTmp, outputFinal)
+	if err != nil {
+		cleanup(outputTmp)
+
+		return fmt.Errorf("atomic rename for %s: %w", dayStr, err)
+	}
+
+	info, err := os.Stat(outputFinal)
+	if err != nil {
+		return fmt.Errorf("stat final output: %w", err)
+	}
+
+	slog.Info("day completed", "date", dayStr,
+		"path", outputFinal, "size_bytes", info.Size())
 
 	return nil
 }

internal/bsdaily/snapshot.go

@@ -1,6 +1,7 @@
 package bsdaily
 
 import (
+	"errors"
 	"fmt"
 	"log/slog"
 	"os"
@@ -9,10 +10,15 @@ import (
 	"time"
 )
 
-func FindLatestDailySnapshot() (dir string, snapshotDate time.Time, err error) {
+var errNoSnapshots = errors.New("no daily snapshots found")
+
+// FindLatestDailySnapshot locates the newest daily ZFS snapshot that
+// contains the firehose database and returns its directory and date.
+func FindLatestDailySnapshot() (string, time.Time, error) {
 	entries, err := os.ReadDir(SnapshotBase)
 	if err != nil {
-		return "", time.Time{}, fmt.Errorf("reading snapshot directory %s: %w", SnapshotBase, err)
+		return "", time.Time{}, fmt.Errorf(
+			"reading snapshot directory %s: %w", SnapshotBase, err)
 	}
 
 	type snapshot struct {
@@ -21,24 +27,30 @@ func FindLatestDailySnapshot() (dir string, snapshotDate time.Time, err error) {
 	}
 
 	var snapshots []snapshot
+
 	for _, e := range entries {
 		if !e.IsDir() {
 			continue
 		}
+
 		m := snapshotPattern.FindStringSubmatch(e.Name())
 		if m == nil {
 			continue
 		}
-		d, err := time.Parse("2006-01-02", m[1])
+
-		if err != nil {
+		d, perr := time.Parse("2006-01-02", m[1])
-			slog.Warn("skipping snapshot with unparseable date", "name", e.Name(), "error", err)
+		if perr != nil {
+			slog.Warn("skipping snapshot with unparseable date",
+				"name", e.Name(), "error", perr)
+
 			continue
 		}
+
 		snapshots = append(snapshots, snapshot{name: e.Name(), date: d})
 	}
 
 	if len(snapshots) == 0 {
-		return "", time.Time{}, fmt.Errorf("no daily snapshots found in %s", SnapshotBase)
+		return "", time.Time{}, fmt.Errorf("%w in %s", errNoSnapshots, SnapshotBase)
 	}
 
 	sort.Slice(snapshots, func(i, j int) bool {
@@ -46,11 +58,14 @@ func FindLatestDailySnapshot() (dir string, snapshotDate time.Time, err error) {
 	})
 
 	latest := snapshots[0]
-	dir = filepath.Join(SnapshotBase, latest.name)
+	dir := filepath.Join(SnapshotBase, latest.name)
 
 	dbPath := filepath.Join(dir, DBFilename)
-	if _, err := os.Stat(dbPath); err != nil {
+
-		return "", time.Time{}, fmt.Errorf("database not found in snapshot %s: %w", dir, err)
+	_, err = os.Stat(dbPath)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf(
+			"database not found in snapshot %s: %w", dir, err)
 	}
 
 	return dir, latest.date, nil

internal/bsdaily/verify.go

@@ -1,71 +1,147 @@
 package bsdaily
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"log/slog"
+	"os"
 	"os/exec"
 	"strings"
 )
 
-func VerifyOutput(path string) error {
+var (
-	slog.Info("running zstdmt integrity check")
+	errEmptyDecompressed = errors.New("decompressed content is empty")
-	testCmd := exec.Command("zstdmt", "--test", path)
+	errNotSQL            = errors.New("decompressed content does not look like SQL")
-	var testStderr strings.Builder
+)
-	testCmd.Stderr = &testStderr
+
-	if err := testCmd.Run(); err != nil {
+// killCat terminates the zstdcat process, ignoring the benign case where it
-		return fmt.Errorf("zstdmt --test failed: %w; stderr: %s", err, testStderr.String())
+// has already exited (e.g. after receiving SIGPIPE when head closed the pipe)
+// and logging any other failure.
+func killCat(cmd *exec.Cmd) {
+	if cmd.Process == nil {
+		return
 	}
+
+	err := cmd.Process.Kill()
+	if err != nil && !errors.Is(err, os.ErrProcessDone) {
+		slog.Warn("failed to kill zstdcat process", "error", err)
+	}
+}
+
+// VerifyOutput checks that the compressed file at path passes a zstdmt
+// integrity test and that its decompressed head looks like SQL text.
+func VerifyOutput(path string) error {
+	ctx := context.Background()
+
+	slog.Info("running zstdmt integrity check")
+
+	//nolint:gosec // zstdmt with internally constructed path
+	testCmd := exec.CommandContext(ctx, "zstdmt", "--test", path)
+
+	var testStderr strings.Builder
+
+	testCmd.Stderr = &testStderr
+
+	err := testCmd.Run()
+	if err != nil {
+		return fmt.Errorf("zstdmt --test failed: %w; stderr: %s",
+			err, testStderr.String())
+	}
+
 	slog.Info("zstdmt integrity check passed")
 
 	slog.Info("verifying SQL content")
-	catCmd := exec.Command("zstdcat", path)
-	headCmd := exec.Command("head", fmt.Sprintf("-%d", verificationHeadLines))
 
-	pipe, err := catCmd.StdoutPipe()
+	content, err := readDecompressedHead(ctx, path)
 	if err != nil {
-		return fmt.Errorf("creating zstdcat pipe: %w", err)
+		return err
-	}
-	headCmd.Stdin = pipe
-
-	var headOut strings.Builder
-	headCmd.Stdout = &headOut
-
-	if err := catCmd.Start(); err != nil {
-		return fmt.Errorf("starting zstdcat: %w", err)
-	}
-	if err := headCmd.Start(); err != nil {
-		catCmd.Process.Kill() // Clean up if head fails to start
-		return fmt.Errorf("starting head: %w", err)
 	}
 
-	// Wait for head first (it will exit when it has enough lines)
+	err = verifySQLContent(content)
-	if err := headCmd.Wait(); err != nil {
+	if err != nil {
-		catCmd.Process.Kill()
+		return err
-		return fmt.Errorf("head command failed: %w", err)
-	}
-
-	// Kill zstdcat since head closed the pipe (expected SIGPIPE)
-	catCmd.Process.Kill()
-	_ = catCmd.Wait() // Reap the process
-
-	content := headOut.String()
-	if len(content) == 0 {
-		return fmt.Errorf("decompressed content is empty")
-	}
-
-	hasSQLMarker := false
-	for _, marker := range []string{"BEGIN TRANSACTION", "CREATE TABLE", "INSERT INTO", "PRAGMA"} {
-		if strings.Contains(content, marker) {
-			hasSQLMarker = true
-			break
-		}
-	}
-	const verificationSampleBytes = 200
-	if !hasSQLMarker {
-		return fmt.Errorf("decompressed content does not look like SQL; first %d bytes: %s",
-			verificationSampleBytes, content[:min(verificationSampleBytes, len(content))])
 	}
 
 	slog.Info("SQL content verification passed")
+
+	return nil
+}
+
+// readDecompressedHead returns the first verificationHeadLines lines of
+// the decompressed file at path via a zstdcat | head pipeline.
+func readDecompressedHead(ctx context.Context, path string) (string, error) {
+	headArg := fmt.Sprintf("-%d", verificationHeadLines)
+
+	//nolint:gosec // zstdcat with internally constructed path
+	catCmd := exec.CommandContext(ctx, "zstdcat", path)
+	//nolint:gosec // head with fixed numeric argument
+	headCmd := exec.CommandContext(ctx, "head", headArg)
+
+	pipe, err := catCmd.StdoutPipe()
+	if err != nil {
+		return "", fmt.Errorf("creating zstdcat pipe: %w", err)
+	}
+
+	headCmd.Stdin = pipe
+
+	var headOut strings.Builder
+
+	headCmd.Stdout = &headOut
+
+	err = catCmd.Start()
+	if err != nil {
+		return "", fmt.Errorf("starting zstdcat: %w", err)
+	}
+
+	err = headCmd.Start()
+	if err != nil {
+		killCat(catCmd) // Clean up if head fails to start
+
+		return "", fmt.Errorf("starting head: %w", err)
+	}
+
+	// Wait for head first (it will exit when it has enough lines)
+	err = headCmd.Wait()
+	if err != nil {
+		killCat(catCmd)
+
+		return "", fmt.Errorf("head command failed: %w", err)
+	}
+
+	// Kill zstdcat since head closed the pipe (expected SIGPIPE)
+	killCat(catCmd)
+
+	_ = catCmd.Wait() // Reap the process
+
+	return headOut.String(), nil
+}
+
+// verifySQLContent checks that content is non-empty and contains a
+// recognizable SQL marker.
+func verifySQLContent(content string) error {
+	if len(content) == 0 {
+		return errEmptyDecompressed
+	}
+
+	hasSQLMarker := false
+	markers := []string{"BEGIN TRANSACTION", "CREATE TABLE", "INSERT INTO", "PRAGMA"}
+
+	for _, marker := range markers {
+		if strings.Contains(content, marker) {
+			hasSQLMarker = true
+
+			break
+		}
+	}
+
+	const verificationSampleBytes = 200
+
+	if !hasSQLMarker {
+		return fmt.Errorf("%w; first %d bytes: %s", errNotSQL,
+			verificationSampleBytes,
+			content[:min(verificationSampleBytes, len(content))])
+	}
+
 	return nil
 }

script/bootstrap

@@ -0,0 +1,73 @@
+#!/bin/sh
+# script/bootstrap: install all dependencies needed to build and develop
+# 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).
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+PKGMGR=""
+SUDO=""
+
+detect_pkgmgr() {
+    [ -n "$PKGMGR" ] && return 0
+    if command -v nix-env >/dev/null 2>&1; then
+        PKGMGR="nix"
+    elif command -v apt-get >/dev/null 2>&1; then
+        PKGMGR="apt"
+    elif command -v brew >/dev/null 2>&1; then
+        PKGMGR="brew"
+    elif command -v apk >/dev/null 2>&1; then
+        PKGMGR="apk"
+    else
+        echo "bootstrap: no supported package manager (nix, apt, brew, apk)" >&2
+        exit 1
+    fi
+    if [ "$PKGMGR" = "apt" ]; then
+        export DEBIAN_FRONTEND=noninteractive
+        if [ "$(id -u)" != "0" ]; then
+            SUDO="sudo"
+        fi
+    fi
+}
+
+# pkg_install <nix-attr> <apt-pkg> <brew-formula> <apk-pkg>
+pkg_install() {
+    detect_pkgmgr
+    case "$PKGMGR" in
+        nix) nix-env -iA "nixpkgs.$1" ;;
+        apt) $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y "$2" ;;
+        brew) brew install "$3" ;;
+        apk) apk add --no-cache "$4" ;;
+    esac
+}
+
+missing() {
+    ! command -v "$1" >/dev/null 2>&1
+}
+
+main() {
+    cd "$ROOT"
+
+    # Base tooling (every repo)
+    if missing git; then pkg_install git git git git; fi
+    if missing make; then pkg_install gnumake make make make; fi
+
+    # Go toolchain
+    if missing go; then pkg_install go golang go go; fi
+
+    # golangci-lint: packaged in nix, brew, and apk. There is no apt
+    # package; on apt systems install it manually from a hash-verified
+    # GitHub release archive (never curl | sh).
+    if missing golangci-lint; then
+        pkg_install golangci-lint golangci-lint golangci-lint golangci-lint
+    fi
+
+    go mod download
+
+    echo "bootstrap complete"
+}
+
+main "$@"

script/check

@@ -0,0 +1,15 @@
+#!/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.
+# Generic: usually needs no adaptation.
+set -eu
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+
+main() {
+    "$SCRIPT_DIR/test"
+    "$SCRIPT_DIR/lint"
+    "$SCRIPT_DIR/fmt-check"
+}
+
+main "$@"

script/cibuild

@@ -0,0 +1,14 @@
+#!/bin/sh
+# script/cibuild: run the CI build. The Dockerfile runs script/check
+# (via make check), so a successful build implies all checks pass.
+# Generic: needs no adaptation. The Gitea workflow runs this on push.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    docker build .
+}
+
+main "$@"

script/docker

@@ -0,0 +1,15 @@
+#!/bin/sh
+# script/docker: build the Docker image tagged with the project name.
+# Identical in all repos; the tag comes from script/projectname.
+# Generic: needs no adaptation.
+set -eu
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    docker build -t "$("$SCRIPT_DIR/projectname")" .
+}
+
+main "$@"

script/fmt

@@ -0,0 +1,12 @@
+#!/bin/sh
+# script/fmt: format all files (writes).
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    go fmt ./...
+}
+
+main "$@"

script/fmt-check

@@ -0,0 +1,18 @@
+#!/bin/sh
+# script/fmt-check: check formatting (read-only). Same scope as
+# script/fmt, but fails instead of writing.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    unformatted="$(gofmt -l .)"
+    if [ -n "$unformatted" ]; then
+        echo "Files not formatted:" >&2
+        echo "$unformatted" >&2
+        exit 1
+    fi
+}
+
+main "$@"

script/install-precommit

@@ -0,0 +1,17 @@
+#!/bin/sh
+# script/install-precommit: install the git pre-commit hook that runs
+# script/precommit. Our own extension to scripts-to-rule-them-all.
+# Generic: needs no adaptation.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    hook=".git/hooks/pre-commit"
+    printf '#!/bin/sh\nset -e\nscript/precommit\n' > .git/hooks/pre-commit
+    chmod +x .git/hooks/pre-commit
+    echo "pre-commit hook installed: runs script/precommit"
+}
+
+main "$@"

script/lint

@@ -0,0 +1,12 @@
+#!/bin/sh
+# script/lint: run the linter.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    golangci-lint run ./...
+}
+
+main "$@"

script/precommit

@@ -0,0 +1,21 @@
+#!/bin/sh
+# script/precommit: run by the git pre-commit hook; fails the commit if
+# checks fail. Our own extension to scripts-to-rule-them-all. Go repo
+# extras: go mod tidy and go fmt must leave the tree unchanged.
+set -eu
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    go mod tidy
+    go fmt ./...
+    git diff --exit-code -- go.mod go.sum || {
+        echo "go mod tidy changed files; please stage and retry"
+        exit 1
+    }
+    "$SCRIPT_DIR/check"
+}
+
+main "$@"

script/projectname

@@ -0,0 +1,12 @@
+#!/bin/sh
+# script/projectname: output the name of this project. Our own
+# extension to scripts-to-rule-them-all. Other scripts that need the
+# name (e.g. script/docker) call this, so they can stay identical
+# across all repos.
+set -eu
+
+main() {
+    echo "bsdaily"
+}
+
+main "$@"

script/setup

@@ -0,0 +1,14 @@
+#!/bin/sh
+# script/setup: set up the repo for development after a fresh clone:
+# installs dependencies (script/bootstrap) and the git pre-commit hook.
+# Add any repo-specific initialization (db init, .env template) here.
+set -eu
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd -P)"
+
+main() {
+    "$SCRIPT_DIR/bootstrap"
+    "$SCRIPT_DIR/install-precommit"
+}
+
+main "$@"

script/test

@@ -0,0 +1,18 @@
+#!/bin/sh
+# script/test: run the test suite. Quiet on success; on failure, rerun
+# verbosely for full diagnostic output (the exit 1 ensures the rerun
+# never turns a failure into a pass).
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+main() {
+    cd "$ROOT"
+    go test -race -timeout 30s ./... || {
+        echo "--- Rerunning with -v for details ---"
+        go test -race -timeout 30s -v ./...
+        exit 1
+    }
+}
+
+main "$@"