feat(scanner): add debounced file watching with polling fallback

- Implement event queue with 3-second debouncing for file system events
- Add configurable polling fallback (default 3 min) via SCAN_POLL_INTERVAL_MINUTES
- Add SyncFilesystemWithDatabase to detect orphaned DB entries and new files
- Integrate utils.ResolveMediaURL for consistent media file path resolution
- Add COOKIE_SECURE env var with SameSite=LaxMode for session cookies
- Update media handler to properly decode URL paths for file serving
- Refactor scanner initialization to accept poll interval configuration

internal/handlers/commonhandlers.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"bookhoard/internal/config"
 	"bookhoard/internal/database"
 	"bookhoard/internal/services"
 	wsync "bookhoard/internal/sync"
@@ -27,9 +28,10 @@ type Handler struct {
 	watchingLibraries map[string]bool
 	connManager       *wsync.ConnectionManager
 	cleanupTaskCancel context.CancelFunc
+	config            *config.Config
 }
 
-func NewHandler(db *database.Queries, connManager *wsync.ConnectionManager, queueProcessor *wsync.SyncQueueProcessor) *Handler {
+func NewHandler(db *database.Queries, connManager *wsync.ConnectionManager, queueProcessor *wsync.SyncQueueProcessor, cfg *config.Config) *Handler {
 	ctx, cancel := context.WithCancel(context.Background())
 	worker := services.NewWorker(3)
 	scheduler := services.NewScheduler(worker, db)
@@ -40,7 +42,7 @@ func NewHandler(db *database.Queries, connManager *wsync.ConnectionManager, queu
 
 	return &Handler{
 		db:                db,
-		scanner:           services.NewMediaScanner(db),
+		scanner:           services.NewMediaScanner(db, cfg.ScanPollIntervalMinutes),
 		worker:            worker,
 		scheduler:         scheduler,
 		queueProcessor:    queueProcessor,
@@ -66,6 +68,6 @@ func parseDate(dateStr string) time.Time {
 	return time.Time{}
 }
 
-func SetupRoutes(g *echo.Group, db *database.Queries, connManager *wsync.ConnectionManager, queueProcessor *wsync.SyncQueueProcessor) *Handler {
-	return NewHandler(db, connManager, queueProcessor)
+func SetupRoutes(g *echo.Group, db *database.Queries, connManager *wsync.ConnectionManager, queueProcessor *wsync.SyncQueueProcessor, cfg *config.Config) *Handler {
+	return NewHandler(db, connManager, queueProcessor, cfg)
 }