Update golangci-lint to v2.12.2 with canonical config (#62)

Updates golangci-lint to v2.12.2 everywhere it is pinned and installs the canonical `.golangci.yml`, then remediates every finding the new linter/config surfaces so `make check` is green.

## Version bump

- `Dockerfile` lint stage: `golangci/golangci-lint:v2.11.3-alpine` -> `v2.12.2-alpine` (digest-pinned, date comment updated)
- `Makefile` `deps` target: `go install` moved from the old v1 module path at `@latest` to the pinned `github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.12.2`
- `.golangci.yml` replaced with the canonical config (v2 schema; settings under `linters.settings` so the thresholds actually apply; `default: all` with the standard six disables)
- `script/bootstrap` installs golangci-lint via the system package manager and carries no version pin, so it is unchanged
- CI (`.gitea/workflows/check.yml`) only runs `script/cibuild`, so it needed no change

## Lint remediation

The canonical config surfaced ~3,300 findings across 56k lines. All are fixed, behavior-preserving; incorporates and supersedes the per-package mechanical passes already merged to `main` (refs #61). Highlights:

- `err113`: dynamic errors replaced with package sentinels + `%w` wrapping; comparisons via `errors.Is`
- `goprintffuncname`: printf-style helpers renamed with an `f` suffix (`ui.Writer` message methods, `cli.ReportErrorf`, `database.Fatalf`) and all call sites updated
- `revive` stutter renames: `blob.Handler`, `blob.WithReader`, `blob.ChunkPosition`, `storage.URL`, `storage.Info`; missing doc comments added
- `contextcheck`/`noctx`: `context.Context` threaded through `blob.Packer` and the scanner call sites; context-aware `exec`/`sql` variants
- `funlen`/`cyclop`/`gocognit`/`dupl`: oversized and duplicated functions split into focused helpers (production and test code)
- tests: `t.Parallel()` added where safe (global logger init kept in the serial phase for `-race`), `t.TempDir()`/`t.Helper()` adopted, several suites converted to external test packages
- `gosec`: bounded integer conversions, `ReadHeaderTimeout` on the test HTTP server; remaining warnings suppressed per-site with justifications
- remaining `nolint` directives are rare, targeted, and each carries a reason (e.g. `nilnil` not-found contract in the repository layer, fx module globals, on-disk snake_case struct tags)
- removed the deprecated `log.LogOptions` alias (callers migrated to `log.Options`)

`make check` (tests with `-race`, lint, fmt-check) passes.

Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #62
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

internal/database/cascade_debug_test.go

@@ -1,3 +1,4 @@
+//nolint:testpackage // inspects the unexported database connection
 package database
 
 import (
@@ -9,25 +10,13 @@ import (
 	"sneak.berlin/go/vaultik/internal/types"
 )
 
-// TestCascadeDeleteDebug tests cascade delete with debug output
-func TestCascadeDeleteDebug(t *testing.T) {
-	db, cleanup := setupTestDB(t)
-	defer cleanup()
+// createCascadeFixtures creates a file with three chunk mappings for the
+// cascade-delete test.
+func createCascadeFixtures(t *testing.T, repos *Repositories) *File {
+	t.Helper()
 
 	ctx := context.Background()
-	repos := NewRepositories(db)
 
-	// Check if foreign keys are enabled
-	var fkEnabled int
-
-	err := db.conn.QueryRow("PRAGMA foreign_keys").Scan(&fkEnabled)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	t.Logf("Foreign keys enabled: %d", fkEnabled)
-
-	// Create a file
 	file := &File{
 		Path:  "/cascade-test.txt",
 		MTime: time.Now().Truncate(time.Second),
@@ -37,7 +26,7 @@ func TestCascadeDeleteDebug(t *testing.T) {
 		GID:   1000,
 	}
 
-	err = repos.Files.Create(ctx, nil, file)
+	err := repos.Files.Create(ctx, nil, file)
 	if err != nil {
 		t.Fatalf("failed to create file: %v", err)
 	}
@@ -67,9 +56,56 @@ func TestCascadeDeleteDebug(t *testing.T) {
 			t.Fatalf("failed to create file chunk: %v", err)
 		}
 
-		t.Logf("Created file chunk mapping: file_id=%s, idx=%d, chunk=%s", fc.FileID, fc.Idx, fc.ChunkHash)
+		t.Logf("Created file chunk mapping: file_id=%s, idx=%d, chunk=%s",
+			fc.FileID, fc.Idx, fc.ChunkHash)
 	}
 
+	return file
+}
+
+// logCascadeDebugInfo logs foreign-key state and the file_chunks table
+// definition for cascade-delete debugging.
+func logCascadeDebugInfo(ctx context.Context, t *testing.T, db *DB) {
+	t.Helper()
+
+	// Check if foreign keys are enabled
+	var fkEnabled int
+
+	err := db.conn.QueryRowContext(ctx, "PRAGMA foreign_keys").Scan(&fkEnabled)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("Foreign keys enabled: %d", fkEnabled)
+
+	// Check the foreign key constraint
+	var fkInfo string
+
+	err = db.conn.QueryRowContext(ctx, `
+		SELECT sql FROM sqlite_master
+		WHERE type='table' AND name='file_chunks'
+	`).Scan(&fkInfo)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Logf("file_chunks table definition:\n%s", fkInfo)
+}
+
+// TestCascadeDeleteDebug tests cascade delete with debug output
+func TestCascadeDeleteDebug(t *testing.T) {
+	t.Parallel()
+
+	db, cleanup := setupTestDB(t)
+	defer cleanup()
+
+	ctx := context.Background()
+	repos := NewRepositories(db)
+
+	logCascadeDebugInfo(ctx, t, db)
+
+	file := createCascadeFixtures(t, repos)
+
 	// Verify file chunks exist
 	fileChunks, err := repos.FileChunks.GetByFileID(ctx, file.ID)
 	if err != nil {
@@ -78,19 +114,6 @@ func TestCascadeDeleteDebug(t *testing.T) {
 
 	t.Logf("File chunks before delete: %d", len(fileChunks))
 
-	// Check the foreign key constraint
-	var fkInfo string
-
-	err = db.conn.QueryRow(`
-		SELECT sql FROM sqlite_master 
-		WHERE type='table' AND name='file_chunks'
-	`).Scan(&fkInfo)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	t.Logf("file_chunks table definition:\n%s", fkInfo)
-
 	// Delete the file
 	t.Log("Deleting file...")
 
@@ -122,7 +145,9 @@ func TestCascadeDeleteDebug(t *testing.T) {
 	// Manually check the database
 	var count int
 
-	err = db.conn.QueryRow("SELECT COUNT(*) FROM file_chunks WHERE file_id = ?", file.ID).Scan(&count)
+	err = db.conn.QueryRowContext(ctx,
+		"SELECT COUNT(*) FROM file_chunks WHERE file_id = ?", file.ID,
+	).Scan(&count)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -133,7 +158,8 @@ func TestCascadeDeleteDebug(t *testing.T) {
 		t.Errorf("expected 0 file chunks after cascade delete, got %d", len(fileChunks))
 		// List the remaining chunks
 		for _, fc := range fileChunks {
-			t.Logf("Remaining chunk: file_id=%s, idx=%d, chunk=%s", fc.FileID, fc.Idx, fc.ChunkHash)
+			t.Logf("Remaining chunk: file_id=%s, idx=%d, chunk=%s",
+				fc.FileID, fc.Idx, fc.ChunkHash)
 		}
 	}
 }