.mp3 upload fix

internal/web_server/handlers/file_handler.go

@@ -156,6 +156,28 @@ func (h *Handler) UploadMedia(c *fiber.Ctx) error {
 			"audio/aac": true, "audio/webm": true, "video/ogg": true, "video/webm": true,
 			"audio/x-wav": true, "audio/x-m4a": true, "audio/flac": true,
 		}
+		// DetectContentType can return "application/octet-stream" for some files (often via clients
+		// like Postman). If that happens, fall back to extension-based detection.
+		if contentType == "application/octet-stream" {
+			filenameLower := strings.ToLower(fileHeader.Filename)
+			lastDot := strings.LastIndex(filenameLower, ".")
+			ext := ""
+			if lastDot != -1 && lastDot+1 < len(filenameLower) {
+				ext = filenameLower[lastDot+1:]
+			}
+			extMap := map[string]string{
+				"mp3":  "audio/mpeg",
+				"wav":  "audio/wav",
+				"ogg":  "audio/ogg",
+				"m4a":  "audio/mp4",
+				"aac":  "audio/aac",
+				"webm": "audio/webm",
+				"flac": "audio/flac",
+			}
+			if ct, ok := extMap[ext]; ok {
+				contentType = ct
+			}
+		}
 		if !allowedAudio[contentType] {
 			return c.Status(fiber.StatusBadRequest).JSON(domain.ErrorResponse{
 				Message: "Invalid file type",