feat(videos): show conversion progress % and elapsed time

- _converting dict now tracks started_at, source_size, tmp_path per file
- list_local_videos() reads tmp file size to compute pct complete
- Desktop badge: 'Converting 42% 1m30s'
- Mobile badge: '42%' (compact, fits under thumbnail)

Co-authored-by: Copilot <[email protected]>

modules/app_video.py

@@ -17,7 +17,7 @@ CONVERT_SETTING = "video_convert_enabled"
 _thumbnail_lock = Semaphore()
 _generating = set()
 _generating_lock = Semaphore()
-_converting = set()
+_converting = {}   # path -> {"started_at": float, "source_size": int, "tmp_path": str}
 _converting_lock = Semaphore()
 
 
@@ -36,7 +36,7 @@ def queue_convert(relative_path, force=False):
     with _converting_lock:
         if relative_path in _converting:
             return False
-        _converting.add(relative_path)
+        _converting[relative_path] = {"started_at": time.time(), "source_size": 0, "tmp_path": ""}
     t = threading.Thread(target=_convert_bg, args=(relative_path,), daemon=True)
     t.start()
     return True
@@ -53,6 +53,11 @@ def _convert_bg(relative_path):
 
         try:
             tmp_path = mp4_path + ".converting.mp4"
+            source_size = os.path.getsize(source_path) if os.path.exists(source_path) else 0
+            with _converting_lock:
+                if relative_path in _converting:
+                    _converting[relative_path]["source_size"] = source_size
+                    _converting[relative_path]["tmp_path"] = tmp_path
             cmd = [
                 "ffmpeg", "-nostdin", "-loglevel", "error", "-y",
                 "-i", source_path,
@@ -84,7 +89,7 @@ def _convert_bg(relative_path):
             app_dash.end_local_video_use(relative_path)
     finally:
         with _converting_lock:
-            _converting.discard(relative_path)
+            _converting.pop(relative_path, None)
 
 
 def _local_path(relative_path):
@@ -117,7 +122,24 @@ def list_local_videos():
             errors.append(f"{relative_path}: {e}")
             continue
         with _converting_lock:
-            converting = relative_path in _converting
+            conv_info = _converting.get(relative_path)
+        converting = conv_info is not None
+        convert_progress = None
+        if converting and conv_info:
+            elapsed = time.time() - conv_info["started_at"]
+            source_size = conv_info["source_size"]
+            tmp_path = conv_info["tmp_path"]
+            tmp_size = 0
+            if tmp_path and os.path.exists(tmp_path):
+                try:
+                    tmp_size = os.path.getsize(tmp_path)
+                except OSError:
+                    pass
+            pct = round(tmp_size / source_size * 100) if source_size > 0 else 0
+            convert_progress = {
+                "elapsed_s": int(elapsed),
+                "pct": min(pct, 99),  # never show 100% until done
+            }
         files.append(
             {
                 "path": relative_path,
@@ -129,6 +151,7 @@ def list_local_videos():
                     stat.st_mtime,
                 ) in uploaded_stats,
                 "converting": converting,
+                "convert_progress": convert_progress,
             }
         )
         total_size += stat.st_size