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/cli/duration.go

@@ -9,6 +9,21 @@ import (
 	"time"
 )
 
+// Approximate lengths of the extended calendar units accepted by
+// parseDuration.
+const (
+	durationDay   = 24 * time.Hour
+	durationWeek  = 7 * durationDay
+	durationMonth = 30 * durationDay
+	durationYear  = 365 * durationDay
+)
+
+var (
+	errNegativeDuration = errors.New("negative durations are not supported")
+	errInvalidDuration  = errors.New("invalid duration format")
+	errUnknownTimeUnit  = errors.New("unknown time unit")
+)
+
 // parseDuration parses duration strings. Supports standard Go duration format
 // (e.g., "3h30m", "1h45m30s") as well as extended units:
 // - d: days (e.g., "30d", "7d")
@@ -19,14 +34,15 @@ import (
 // Can combine units: "1y6mo", "2w3d", "1d12h30m"
 func parseDuration(s string) (time.Duration, error) {
 	// First try standard Go duration parsing
-	if d, err := time.ParseDuration(s); err == nil {
+	d, err := time.ParseDuration(s)
+	if err == nil {
 		return d, nil
 	}
 
 	// Extended duration parsing
 	// Check for negative values
 	if strings.HasPrefix(strings.TrimSpace(s), "-") {
-		return 0, errors.New("negative durations are not supported")
+		return 0, errNegativeDuration
 	}
 
 	// Pattern matches: number + unit, repeated
@@ -34,7 +50,7 @@ func parseDuration(s string) (time.Duration, error) {
 	matches := re.FindAllStringSubmatch(s, -1)
 
 	if len(matches) == 0 {
-		return 0, fmt.Errorf("invalid duration format: %q", s)
+		return 0, fmt.Errorf("%w: %q", errInvalidDuration, s)
 	}
 
 	var total time.Duration
@@ -48,45 +64,9 @@ func parseDuration(s string) (time.Duration, error) {
 			return 0, fmt.Errorf("invalid number %q: %w", valueStr, err)
 		}
 
-		var d time.Duration
-
-		switch unit {
-		// Standard time units
-		case "ns", "nanosecond", "nanoseconds":
-			d = time.Duration(value)
-		case "us", "µs", "microsecond", "microseconds":
-			d = time.Duration(value * float64(time.Microsecond))
-		case "ms", "millisecond", "milliseconds":
-			d = time.Duration(value * float64(time.Millisecond))
-		case "s", "sec", "second", "seconds":
-			d = time.Duration(value * float64(time.Second))
-		case "m", "min", "minute", "minutes":
-			d = time.Duration(value * float64(time.Minute))
-		case "h", "hr", "hour", "hours":
-			d = time.Duration(value * float64(time.Hour))
-		// Extended units
-		case "d", "day", "days":
-			d = time.Duration(value * float64(24*time.Hour))
-		case "w", "week", "weeks":
-			d = time.Duration(value * float64(7*24*time.Hour))
-		case "mo", "month", "months":
-			// Using 30 days as approximation
-			d = time.Duration(value * float64(30*24*time.Hour))
-		case "y", "year", "years":
-			// Using 365 days as approximation
-			d = time.Duration(value * float64(365*24*time.Hour))
-		default:
-			// Try parsing as standard Go duration unit
-			testStr := "1" + unit
-			if _, err := time.ParseDuration(testStr); err == nil {
-				// It's a valid Go duration unit, parse the full value
-				fullStr := fmt.Sprintf("%g%s", value, unit)
-				if d, err = time.ParseDuration(fullStr); err != nil {
-					return 0, fmt.Errorf("invalid duration %q: %w", fullStr, err)
-				}
-			} else {
-				return 0, fmt.Errorf("unknown time unit %q", unit)
-			}
+		d, err := durationForUnit(value, unit)
+		if err != nil {
+			return 0, err
 		}
 
 		total += d
@@ -94,3 +74,53 @@ func parseDuration(s string) (time.Duration, error) {
 
 	return total, nil
 }
+
+// durationForUnit converts a value with a (case-normalized) unit suffix
+// into a time.Duration, accepting Go's standard units plus the extended
+// calendar units.
+func durationForUnit(value float64, unit string) (time.Duration, error) {
+	switch unit {
+	// Standard time units
+	case "ns", "nanosecond", "nanoseconds":
+		return time.Duration(value), nil
+	case "us", "µs", "microsecond", "microseconds":
+		return time.Duration(value * float64(time.Microsecond)), nil
+	case "ms", "millisecond", "milliseconds":
+		return time.Duration(value * float64(time.Millisecond)), nil
+	case "s", "sec", "second", "seconds":
+		return time.Duration(value * float64(time.Second)), nil
+	case "m", "min", "minute", "minutes":
+		return time.Duration(value * float64(time.Minute)), nil
+	case "h", "hr", "hour", "hours":
+		return time.Duration(value * float64(time.Hour)), nil
+	// Extended units
+	case "d", "day", "days":
+		return time.Duration(value * float64(durationDay)), nil
+	case "w", "week", "weeks":
+		return time.Duration(value * float64(durationWeek)), nil
+	case "mo", "month", "months":
+		// Using 30 days as approximation
+		return time.Duration(value * float64(durationMonth)), nil
+	case "y", "year", "years":
+		// Using 365 days as approximation
+		return time.Duration(value * float64(durationYear)), nil
+	default:
+		// Try parsing as standard Go duration unit
+		testStr := "1" + unit
+
+		_, err := time.ParseDuration(testStr)
+		if err != nil {
+			return 0, fmt.Errorf("%w: %q", errUnknownTimeUnit, unit)
+		}
+
+		// It's a valid Go duration unit, parse the full value
+		fullStr := fmt.Sprintf("%g%s", value, unit)
+
+		d, err := time.ParseDuration(fullStr)
+		if err != nil {
+			return 0, fmt.Errorf("invalid duration %q: %w", fullStr, err)
+		}
+
+		return d, nil
+	}
+}