refactor: process files concurrently and add stability check before queueing while ignoring the binary output

.gitignore

@@ -1 +1,2 @@
-media/
+media/
+goencode

internal/watcher/watcher.go

@@ -138,7 +138,7 @@ func (m *Manager) processWorker() {
 		case <-m.stopChan:
 			return
 		case path := <-m.processChan:
-			m.processFile(path)
+			go m.processFile(path)
 		}
 	}
 }
@@ -151,7 +151,7 @@ func (m *Manager) handleEvent(filePath string) {
 		t.Stop()
 	}
 
-	m.timers[filePath] = time.AfterFunc(5*time.Second, func() {
+	m.timers[filePath] = time.AfterFunc(2*time.Minute, func() {
 		m.timersMu.Lock()
 		delete(m.timers, filePath)
 		m.timersMu.Unlock()
@@ -176,6 +176,31 @@ func (m *Manager) processFile(filePath string) {
 		return
 	}
 
+	// Wait until the file is fully copied and stable
+	var lastSize int64 = info.Size()
+	var lastModTime time.Time = info.ModTime()
+	var stableCount int
+
+	for {
+		time.Sleep(5 * time.Second)
+		currentInfo, err := os.Stat(filePath)
+		if err != nil {
+			return // File was likely deleted during copying
+		}
+
+		if currentInfo.Size() == lastSize && currentInfo.ModTime().Equal(lastModTime) {
+			stableCount++
+			if stableCount >= 3 { // Stable for 15 seconds
+				break
+			}
+		} else {
+			stableCount = 0
+			lastSize = currentInfo.Size()
+			lastModTime = currentInfo.ModTime()
+		}
+	}
+
+	// Re-check after waiting
 	alreadyInQueue, err := db.IsFileAlreadyProcessedOrQueued(filePath)
 	if err != nil {
 		log.Printf("Error checking DB for %s: %v", filePath, err)