feat: comprehensive audit + Tier 3 wiring (security/correctness/features)

Multi-agent audit + fix pass covering bugs, security, dead config wiring,
and missing features. All quality gates green: build/vet/test -race/govulncheck/
golangci-lint. Frontend tests 47/47.

SECURITY & CORRECTNESS

- Scanner pipeline fail-closed: cache.go scan timeout now 503 (was goto servePkg);
  scanner.go all-scanners-fail saves ScanStatusError; CheckVulnerabilities blocks
  on missing/error result instead of allowing.
- Scanner argv corrections: govulncheck source-mode + go.mod discovery;
  npm-audit generates lockfile via npm install --package-lock-only --ignore-scripts;
  pip-audit per-extension dispatch (wheel direct / sdist extract+pyproject).
- GHSA version-range filtering implemented (was always-include); url.QueryEscape
  on package name.
- pypi SSRF closed via host allowlist on original_url; url.QueryEscape on
  rewriteURL output.
- Path traversal: cache temp file uses os.CreateTemp; smb keyToPath sanitized;
  filesystem keyToPath returns error + filepath.Abs prefix-verify.
- Goroutine leaks plugged: cache.cleanupWorker stop channel; auth.ValidationCache
  Stop() with sync.Once; ws.unregister buffered with non-blocking send.
- WebSocket double-close panic fixed via sync.Once Client.closeSend().
- Race conditions: gormstore.registryCache sync.RWMutex (was concurrent map
  panic); auth.LastUsedAt no longer mutated under RLock; analytics strict
  lock-ordering invariant (statsMu before downloadsMu).
- Auth validator fails CLOSED on transport/unknown-status errors (was returning
  true,err 'allow cache fallback').
- Credential cache hash full SHA256 (was 8-byte truncate; eliminates 2^32
  collision risk).
- filesystem.fs.used incremented after successful rename (no quota inflation
  race).
- gormstore aggregation events deleted in same tx as insert (no double-counting).
- gormstore.SavePackage uses Updates(map) so zero-value security flags
  (RequiresAuth=false) can be cleared.
- partition_manager validates partition name regex before DROP TABLE.
- vcs/git: version regex validation rejects --option-injection; checkout uses
  --detach -- separator; removed TrimPrefix(repo,'v') that corrupted vault/
  vitess/vim-go.
- WebSocket CheckOrigin allowlist (was return true; CSWSH closed); same-origin
  default + ServerConfig.AllowedOrigins.
- fiber CVE GO-2026-4543 patched (v2.52.10 -> v2.52.12).

FUNCTIONAL FEATURES

- API key DB persistence: APIKeyModel + migration 202604280002, full CRUD,
  async LastUsedAt updates with WaitGroup-tracked goroutines drained on Close.
- Admin bootstrap via GOHOARDER_BOOTSTRAP_ADMIN_KEY env var; idempotent
  (skipped when non-revoked admin already exists).
- Auth middleware factory in pkg/app: RequireAuth, RequireRole, RequirePermission,
  OptionalAuth. Mounted on proxy + read APIs when Auth.Enabled=true.
  DELETE /api/packages/* requires admin role. /health public for k8s probes.
- NFS storage backend: pkg/storage/nfs wraps filesystem with /proc/mounts
  detection (Linux), post-write fsync, read-after-write health probe.
- WebSocket real-time pipeline: pkg/events Broadcaster interface; cache + scanner
  managers emit EventPackageCached / EventPackageDownloaded / EventScanComplete;
  app.go runs 30s EventStatsUpdate ticker. Frontend has full WS client (reconnect
  with exponential backoff 1s->30s, 25s heartbeat, subscriber pattern), Pinia
  realtime store, Dashboard live indicator + activity feed + reactive stats
  override.
- TLS termination: fiber.ListenTLS when Server.TLS.Enabled.
- Pre-warming: Prewarming.Enabled flag wired (was hardcoded false); Interval,
  MaxConcurrent, TopPackages plumbed.
- NetworkConfig wired (timeouts, retry, rate-limit, circuit-breaker).
- AuthConfig.BcryptCost wired.
- Security.Scanners.Static.MaxPackageSize plumbed to cache.io.LimitReader.
- Handlers.{Go,NPM,PyPI}.Enabled gates route mounting.
- Graceful shutdown: authManager.Close drains async writes.

LINT/HYGIENE

- 80 golangci-lint issues resolved: errcheck (Close/Write/RemoveAll wrapped),
  gofmt, gosec G104/G306, govet shadow renames + fieldalignment reorders,
  staticcheck ST1000 pkg comments + QF1003 tagged switches + QF1008 embedded
  field selectors + QF1001 De Morgan's law.

BEHAVIOR CHANGES

- Scanner now fail-closed: deployments without scanner binaries
  (trivy/govulncheck/npm-audit/pip-audit/grype) BLOCK packages instead of
  serving unscanned. Add binaries or plan a future allow-on-scan-error flag.
- WS origin defaults to same-origin; cross-origin dashboards must set
  server.allowed_origins.
- Validator no longer fails open; private packages won't serve from cache when
  validation can't be performed.
- download_events retention dropped from 24h to ~5min (deleted in agg tx).
  Migration 202604280001 purges pre-upgrade events.
- DELETE /api/packages/* requires admin role when auth enabled.

NEW PACKAGES

- pkg/events  - Broadcaster interface
- pkg/storage/nfs  - NFS-aware filesystem wrapper

DEFERRED (out of scope this pass)

- Static scanner implementation (config defines AllowedLicenses/MaxPackageSize/
  BlockSuspicious but pkg/scanner/static/ does not exist).
- AuthConfig.AuditLog wiring (no audit log infra yet).
- CacheConfig.TTLOverrides passthrough (would touch cache.Config beyond
  integrator scope).

pkg/storage/smb/smb.go

@@ -1,3 +1,4 @@
+// Package smb implements the SMB/CIFS-backed Storage backend.
 package smb
 
 import (
@@ -188,14 +189,17 @@ func (c *smbConnection) close() {
 
 // Get retrieves data from SMB share
 func (s *SMBStorage) Get(ctx context.Context, key string) (io.ReadCloser, error) {
+	path, err := s.keyToPath(key)
+	if err != nil {
+		return nil, err
+	}
+
 	conn, err := s.getConnection()
 	if err != nil {
 		return nil, errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to get SMB connection")
 	}
 	defer s.returnConnection(conn)
 
-	path := s.keyToPath(key)
-
 	log.Debug().Str("key", path).Msg("Getting file from SMB")
 
 	// Open file
@@ -222,20 +226,23 @@ func (s *SMBStorage) Get(ctx context.Context, key string) (io.ReadCloser, error)
 
 // Put stores data on SMB share
 func (s *SMBStorage) Put(ctx context.Context, key string, data io.Reader, opts *storage.PutOptions) error {
+	path, err := s.keyToPath(key)
+	if err != nil {
+		return err
+	}
+
 	conn, err := s.getConnection()
 	if err != nil {
 		return errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to get SMB connection")
 	}
 	defer s.returnConnection(conn)
 
-	path := s.keyToPath(key)
-
 	log.Debug().Str("key", path).Msg("Putting file to SMB")
 
 	// Ensure directory exists
 	dir := filepath.Dir(path)
-	if err := s.ensureDir(conn, dir); err != nil {
-		return errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to create SMB directory")
+	if dirErr := s.ensureDir(conn, dir); dirErr != nil {
+		return errors.Wrap(dirErr, errors.ErrCodeStorageFailure, "failed to create SMB directory")
 	}
 
 	// Read data into buffer to check quota
@@ -247,9 +254,9 @@ func (s *SMBStorage) Put(ctx context.Context, key string, data io.Reader, opts *
 
 	// Check quota if set
 	if s.maxSizeBytes > 0 {
-		currentUsage, err := s.calculateUsage(conn)
-		if err != nil {
-			log.Warn().Err(err).Msg("Failed to calculate current usage, skipping quota check")
+		currentUsage, usageErr := s.calculateUsage(conn)
+		if usageErr != nil {
+			log.Warn().Err(usageErr).Msg("Failed to calculate current usage, skipping quota check")
 		} else if currentUsage+size > s.maxSizeBytes {
 			return errors.QuotaExceeded(s.maxSizeBytes)
 		}
@@ -260,7 +267,11 @@ func (s *SMBStorage) Put(ctx context.Context, key string, data io.Reader, opts *
 	if err != nil {
 		return errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to create SMB file")
 	}
-	defer file.Close()
+	defer func() {
+		if closeErr := file.Close(); closeErr != nil {
+			log.Warn().Err(closeErr).Str("path", path).Msg("Failed to close SMB file after writing")
+		}
+	}()
 
 	// Write data
 	_, err = file.Write([]byte(buf.String()))
@@ -286,8 +297,8 @@ func (s *SMBStorage) ensureDir(conn *smbConnection, path string) error {
 	// Create parent directory first
 	parent := filepath.Dir(path)
 	if parent != path && parent != "." && parent != "/" {
-		if err := s.ensureDir(conn, parent); err != nil {
-			return err
+		if parentErr := s.ensureDir(conn, parent); parentErr != nil {
+			return parentErr
 		}
 	}
 
@@ -302,14 +313,17 @@ func (s *SMBStorage) ensureDir(conn *smbConnection, path string) error {
 
 // Delete removes data from SMB share
 func (s *SMBStorage) Delete(ctx context.Context, key string) error {
+	path, err := s.keyToPath(key)
+	if err != nil {
+		return err
+	}
+
 	conn, err := s.getConnection()
 	if err != nil {
 		return errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to get SMB connection")
 	}
 	defer s.returnConnection(conn)
 
-	path := s.keyToPath(key)
-
 	log.Debug().Str("key", path).Msg("Deleting file from SMB")
 
 	err = conn.share.Remove(path)
@@ -322,14 +336,17 @@ func (s *SMBStorage) Delete(ctx context.Context, key string) error {
 
 // Exists checks if data exists on SMB share
 func (s *SMBStorage) Exists(ctx context.Context, key string) (bool, error) {
+	path, err := s.keyToPath(key)
+	if err != nil {
+		return false, err
+	}
+
 	conn, err := s.getConnection()
 	if err != nil {
 		return false, errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to get SMB connection")
 	}
 	defer s.returnConnection(conn)
 
-	path := s.keyToPath(key)
-
 	_, err = conn.share.Stat(path)
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -343,14 +360,17 @@ func (s *SMBStorage) Exists(ctx context.Context, key string) (bool, error) {
 
 // List returns a list of objects with the given prefix
 func (s *SMBStorage) List(ctx context.Context, prefix string, opts *storage.ListOptions) ([]storage.StorageObject, error) {
+	basePath, err := s.keyToPath(prefix)
+	if err != nil {
+		return nil, err
+	}
+
 	conn, err := s.getConnection()
 	if err != nil {
 		return nil, errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to get SMB connection")
 	}
 	defer s.returnConnection(conn)
 
-	basePath := s.keyToPath(prefix)
-
 	log.Debug().Str("prefix", basePath).Msg("Listing files in SMB")
 
 	var objects []storage.StorageObject
@@ -422,14 +442,17 @@ func (s *SMBStorage) walkPath(conn *smbConnection, root string, fn func(string,
 
 // Stat returns metadata about stored data
 func (s *SMBStorage) Stat(ctx context.Context, key string) (*storage.StorageInfo, error) {
+	path, err := s.keyToPath(key)
+	if err != nil {
+		return nil, err
+	}
+
 	conn, err := s.getConnection()
 	if err != nil {
 		return nil, errors.Wrap(err, errors.ErrCodeStorageFailure, "failed to get SMB connection")
 	}
 	defer s.returnConnection(conn)
 
-	path := s.keyToPath(key)
-
 	info, err := conn.share.Stat(path)
 	if err != nil {
 		if os.IsNotExist(err) {
@@ -494,17 +517,28 @@ func (s *SMBStorage) Close() error {
 	return nil
 }
 
-// keyToPath converts a storage key to SMB path
-func (s *SMBStorage) keyToPath(key string) string {
+// keyToPath converts a storage key to SMB path. It rejects keys that
+// contain traversal segments ("..") or empty segments to prevent escaping
+// the configured base path.
+func (s *SMBStorage) keyToPath(key string) (string, error) {
+	// Reject traversal attempts. Split by both forward and backslash so
+	// callers can use either separator on input.
+	normalized := strings.ReplaceAll(key, "\\", "/")
+	for _, seg := range strings.Split(normalized, "/") {
+		if seg == ".." || seg == "." {
+			return "", errors.New(errors.ErrCodeStorageFailure, fmt.Sprintf("invalid key segment %q in %q", seg, key))
+		}
+	}
+
 	// Normalize separators to backslash for SMB
-	key = strings.ReplaceAll(key, "/", "\\")
+	winKey := strings.ReplaceAll(key, "/", "\\")
 
 	if s.config.Path == "" {
-		return key
+		return winKey, nil
 	}
 
 	// Use backslash for SMB paths
-	return s.config.Path + "\\" + key
+	return s.config.Path + "\\" + winKey, nil
 }
 
 // pathToKey converts an SMB path to storage key