huge refactor of the entire codebase, with the goal of improving maintainability, readability, and extensibility. This commit includes changes to almost every file in the project, including:

cmdlet/merge_file.py

@@ -154,47 +154,7 @@ def _run(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
 
     if urls_to_download and len(urls_to_download) >= 2:
         try:
-            # Compute a batch hint (audio vs video + single-format id) once.
-            mode_hint: Optional[str] = None
-            forced_format: Optional[str] = None
-            try:
-                from tool.ytdlp import YtDlpTool, list_formats
-
-                sample_url = urls_to_download[0]
-                cookiefile = None
-                try:
-                    cookie_path = YtDlpTool(config).resolve_cookiefile()
-                    if cookie_path is not None and cookie_path.is_file():
-                        cookiefile = str(cookie_path)
-                except Exception:
-                    cookiefile = None
-
-                fmts = list_formats(
-                    sample_url,
-                    no_playlist=False,
-                    playlist_items=None,
-                    cookiefile=cookiefile
-                )
-                if isinstance(fmts, list) and fmts:
-                    has_video = False
-                    for f in fmts:
-                        if not isinstance(f, dict):
-                            continue
-                        vcodec = str(f.get("vcodec", "none") or "none").strip().lower()
-                        if vcodec and vcodec != "none":
-                            has_video = True
-                            break
-                    mode_hint = "video" if has_video else "audio"
-
-                    if len(fmts) == 1 and isinstance(fmts[0], dict):
-                        fid = str(fmts[0].get("format_id") or "").strip()
-                        if fid:
-                            forced_format = fid
-            except Exception:
-                mode_hint = None
-                forced_format = None
-
-            from cmdlet.download_file import Download_File
+            from ProviderCore.registry import get_plugin_for_url
 
             expanded: List[Dict[str, Any]] = []
             downloaded_any = False
@@ -207,12 +167,18 @@ def _run(result: Any, args: Sequence[str], config: Dict[str, Any]) -> int:
                     expanded.append(it)
                     continue
 
-                downloaded = Download_File.download_streaming_url_as_pipe_objects(
-                    u,
-                    config,
-                    mode_hint=mode_hint,
-                    ytdl_format_hint=forced_format,
-                )
+                downloaded = []
+                try:
+                    plugin = get_plugin_for_url(u, config)
+                except Exception:
+                    plugin = None
+                if plugin is not None and hasattr(plugin, "download_url_as_pipe_objects"):
+                    try:
+                        downloaded = plugin.download_url_as_pipe_objects(u)
+                    except TypeError:
+                        downloaded = plugin.download_url_as_pipe_objects(u, output_dir=None)
+                    except Exception:
+                        downloaded = []
                 if downloaded:
                     expanded.extend(downloaded)
                     downloaded_any = True