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/config/config.go

@@ -7,35 +7,37 @@ import (
 )
 
 type Config struct {
-	ServerPort        string
-	BaseURL           string
-	JWTSecret         string
-	UploadPath        string
-	DatabaseHost      string
-	DatabasePort      string
-	DatabaseUser      string
-	DatabasePassword  string
-	DatabaseName      string
-	TestMode          bool
-	RateLimitEnabled  bool
-	RequestsPerMinute int
+	ServerPort              string
+	BaseURL                 string
+	JWTSecret               string
+	UploadPath              string
+	DatabaseHost            string
+	DatabasePort            string
+	DatabaseUser            string
+	DatabasePassword        string
+	DatabaseName            string
+	TestMode                bool
+	RateLimitEnabled        bool
+	RequestsPerMinute       int
+	ScanPollIntervalMinutes int `env:"SCAN_POLL_INTERVAL_MINUTES" default:"3"`
 }
 
 func LoadConfig() *Config {
 	port := getEnv("SERVER_PORT", "8765")
 	return &Config{
-		ServerPort:        port,
-		BaseURL:           getEnv("BASE_URL", "http://localhost:"+port),
-		DatabaseHost:      getEnv("DATABASE_HOST", "localhost"),
-		DatabasePort:      getEnv("DATABASE_PORT", "5432"),
-		DatabaseUser:      getEnv("DATABASE_USER", "postgres"),
-		DatabasePassword:  getEnv("DATABASE_PASSWORD", "password"),
-		DatabaseName:      getEnv("DATABASE_NAME", "bookhoard"),
-		JWTSecret:         getEnv("JWT_SECRET", "your-secret-key"),
-		UploadPath:        getEnv("UPLOAD_PATH", "./uploads"),
-		TestMode:          getEnvBool("TEST_MODE", false),
-		RateLimitEnabled:  getEnvBool("RATE_LIMIT_ENABLED", true),
-		RequestsPerMinute: getEnvInt("REQUESTS_PER_MINUTE", 10),
+		ServerPort:              port,
+		BaseURL:                 getEnv("BASE_URL", "http://localhost:"+port),
+		DatabaseHost:            getEnv("DATABASE_HOST", "localhost"),
+		DatabasePort:            getEnv("DATABASE_PORT", "5432"),
+		DatabaseUser:            getEnv("DATABASE_USER", "postgres"),
+		DatabasePassword:        getEnv("DATABASE_PASSWORD", "password"),
+		DatabaseName:            getEnv("DATABASE_NAME", "bookhoard"),
+		JWTSecret:               getEnv("JWT_SECRET", "your-secret-key"),
+		UploadPath:              getEnv("UPLOAD_PATH", "./uploads"),
+		TestMode:                getEnvBool("TEST_MODE", false),
+		RateLimitEnabled:        getEnvBool("RATE_LIMIT_ENABLED", true),
+		RequestsPerMinute:       getEnvInt("REQUESTS_PER_MINUTE", 10),
+		ScanPollIntervalMinutes: getEnvInt("SCAN_POLL_INTERVAL_MINUTES", 3),
 	}
 }