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/uploads.go

@@ -29,7 +29,9 @@ func NewUploadRepository(conn *sql.DB) *UploadRepository {
 }
 
 // Create inserts a new upload record
-func (r *UploadRepository) Create(ctx context.Context, tx *sql.Tx, upload *Upload) error {
+func (r *UploadRepository) Create(
+	ctx context.Context, tx *sql.Tx, upload *Upload,
+) error {
 	query := `
 		INSERT INTO uploads (blob_hash, snapshot_id, uploaded_at, size, duration_ms)
 		VALUES (?, ?, ?, ?, ?)
@@ -37,16 +39,22 @@ func (r *UploadRepository) Create(ctx context.Context, tx *sql.Tx, upload *Uploa
 
 	var err error
 	if tx != nil {
-		_, err = tx.ExecContext(ctx, query, upload.BlobHash, upload.SnapshotID, upload.UploadedAt, upload.Size, upload.DurationMs)
+		_, err = tx.ExecContext(ctx, query,
+			upload.BlobHash, upload.SnapshotID, upload.UploadedAt,
+			upload.Size, upload.DurationMs)
 	} else {
-		_, err = r.conn.ExecContext(ctx, query, upload.BlobHash, upload.SnapshotID, upload.UploadedAt, upload.Size, upload.DurationMs)
+		_, err = r.conn.ExecContext(ctx, query,
+			upload.BlobHash, upload.SnapshotID, upload.UploadedAt,
+			upload.Size, upload.DurationMs)
 	}
 
 	return err
 }
 
 // GetByBlobHash retrieves an upload record by blob hash
-func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (*Upload, error) {
+func (r *UploadRepository) GetByBlobHash(
+	ctx context.Context, blobHash string,
+) (*Upload, error) {
 	query := `
 		SELECT blob_hash, uploaded_at, size, duration_ms
 		FROM uploads
@@ -63,7 +71,7 @@ func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (
 	)
 
 	if errors.Is(err, sql.ErrNoRows) {
-		return nil, nil
+		return nil, nil //nolint:nilnil // nil,nil signals not-found; callers check nil
 	}
 
 	if err != nil {
@@ -74,7 +82,9 @@ func (r *UploadRepository) GetByBlobHash(ctx context.Context, blobHash string) (
 }
 
 // GetRecentUploads retrieves recent uploads ordered by upload time
-func (r *UploadRepository) GetRecentUploads(ctx context.Context, limit int) ([]*Upload, error) {
+func (r *UploadRepository) GetRecentUploads(
+	ctx context.Context, limit int,
+) ([]*Upload, error) {
 	query := `
 		SELECT blob_hash, uploaded_at, size, duration_ms
 		FROM uploads
@@ -98,7 +108,9 @@ func (r *UploadRepository) GetRecentUploads(ctx context.Context, limit int) ([]*
 	for rows.Next() {
 		var upload Upload
 
-		err := rows.Scan(&upload.BlobHash, &upload.UploadedAt, &upload.Size, &upload.DurationMs)
+		err := rows.Scan(
+			&upload.BlobHash, &upload.UploadedAt, &upload.Size, &upload.DurationMs,
+		)
 		if err != nil {
 			return nil, err
 		}
@@ -110,9 +122,11 @@ func (r *UploadRepository) GetRecentUploads(ctx context.Context, limit int) ([]*
 }
 
 // GetUploadStats returns aggregate statistics for uploads
-func (r *UploadRepository) GetUploadStats(ctx context.Context, since time.Time) (*UploadStats, error) {
+func (r *UploadRepository) GetUploadStats(
+	ctx context.Context, since time.Time,
+) (*UploadStats, error) {
 	query := `
-		SELECT 
+		SELECT
 			COUNT(*) as count,
 			COALESCE(SUM(size), 0) as total_size,
 			COALESCE(AVG(duration_ms), 0) as avg_duration_ms,
@@ -145,7 +159,9 @@ type UploadStats struct {
 }
 
 // GetCountBySnapshot returns the count of uploads for a specific snapshot
-func (r *UploadRepository) GetCountBySnapshot(ctx context.Context, snapshotID string) (int64, error) {
+func (r *UploadRepository) GetCountBySnapshot(
+	ctx context.Context, snapshotID string,
+) (int64, error) {
 	query := `SELECT COUNT(*) FROM uploads WHERE snapshot_id = ?`
 
 	var count int64