Remediate all lint findings under the canonical golangci-lint config

Fix every finding surfaced by the canonical .golangci.yml with
golangci-lint v2.12.2 (refs #61), behavior-preserving throughout:

- err113: dynamic errors replaced with package-level sentinels and %w
  wrapping; direct comparisons converted to errors.Is
- goprintffuncname: printf-style helpers renamed with an f suffix
  (ui.Writer message methods, cli.ReportErrorf, database.Fatalf,
  vaultik stdoutf) and all call sites updated
- revive: stuttering type names renamed (blob.Handler, blob.WithReader,
  blob.ChunkPosition, storage.URL, storage.Info), doc comments added,
  unused parameters blanked, package comments added
- contextcheck/noctx: ctx threaded through blob.Packer
  (AddChunk/Flush/FinalizeBlob/PackChunks) and scanner call sites;
  context-aware exec and sql variants used
- funlen/cyclop/gocognit/nestif/dupl: oversized or duplicated
  functions split into focused helpers across production and test code
- paralleltest/tparallel/thelper/usetesting/testpackage: tests
  parallelized where safe (global log.Initialize kept in the serial
  phase), helpers marked, t.TempDir adopted, external test packages
  where only exported API is used
- gosec: integer conversions clamped or justified, header timeouts
  added, remaining findings suppressed with per-site justifications
- mnd/goconst/lll/wsl_v5/nlreturn/noinlineerr/errcheck and other
  mechanical findings fixed directly

Remove the deprecated log.LogOptions alias (callers migrated to
log.Options). make check is green.

internal/log/tty_handler.go

@@ -94,6 +94,11 @@ func (h *TTYHandler) Handle(_ context.Context, r slog.Record) error {
 			if a.Key == "bytes" {
 				value = formatBytes(a.Value.Int64())
 			}
+		case slog.KindAny, slog.KindBool, slog.KindFloat64, slog.KindString,
+			slog.KindTime, slog.KindUint64, slog.KindGroup, slog.KindLogValuer:
+			// Plain string form above is already correct for these kinds.
+		default:
+			// Future kinds also use the plain string form.
 		}
 
 		_, _ = fmt.Fprintf(h.out, " %s%s%s=%s%s%s",
@@ -109,26 +114,27 @@ func (h *TTYHandler) Handle(_ context.Context, r slog.Record) error {
 }
 
 // WithAttrs returns a new handler with the given attributes.
-func (h *TTYHandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+func (h *TTYHandler) WithAttrs(_ []slog.Attr) slog.Handler {
 	return h // Simplified for now
 }
 
 // WithGroup returns a new handler with the given group name.
-func (h *TTYHandler) WithGroup(name string) slog.Handler {
+func (h *TTYHandler) WithGroup(_ string) slog.Handler {
 	return h // Simplified for now
 }
 
 // formatDuration formats a duration in a human-readable way
 func formatDuration(d time.Duration) string {
-	if d < time.Millisecond {
+	switch {
+	case d < time.Millisecond:
 		return fmt.Sprintf("%dµs", d.Microseconds())
-	} else if d < time.Second {
+	case d < time.Second:
 		return fmt.Sprintf("%dms", d.Milliseconds())
-	} else if d < time.Minute {
+	case d < time.Minute:
 		return fmt.Sprintf("%.1fs", d.Seconds())
+	default:
+		return d.String()
 	}
-
-	return d.String()
 }
 
 // formatBytes formats bytes in a human-readable way