feat(server): route URL/playlist /fetch to download jobs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/actions.py

@@ -61,3 +61,38 @@ def perform_fetch(chosen, hits: list, quality: str, root: str) -> dict:
     if not ok:
         raise RuntimeError("Failed to add artist to Lidarr.")
     return {"path": None, "lidarr_album_id": None}
+
+
+def url_started_message(kind: str, title: str = "") -> str:
+    if kind == "playlist":
+        return (f"Fetching playlist '{title}'. Downloading tracks now."
+                if title else "Fetching playlist. Downloading tracks now.")
+    return f"Fetching '{title}'. Downloading now." if title else "Fetching track. Downloading now."
+
+
+def playlist_done_message(result: dict) -> str:
+    ok, total = result.get("ok", 0), result.get("total", 0)
+    failed = total - ok
+    return f"Downloaded {ok}/{total} tracks" + (f" ({failed} failed)." if failed else ".")
+
+
+def url_done_message(result: dict) -> str:
+    title = result.get("title", "")
+    return f"Downloaded '{title}'." if title else "Download complete."
+
+
+def perform_url_fetch(url: str, quality: str, root: str) -> dict:
+    """Download a URL (playlist -> batch, else single). Raises if nothing
+    downloaded so the job is marked failed."""
+    if mf.is_playlist_url(url):
+        ok, total, title = mf.download_playlist(url, root, quality, False)
+        if ok == 0:
+            raise RuntimeError(f"No tracks downloaded from playlist '{title}'." if title
+                               else "No tracks downloaded from playlist.")
+        return {"kind": "playlist", "title": title, "ok": ok, "total": total,
+                "path": None, "lidarr_album_id": None}
+    info = mf.download_single(url, root, quality, False)
+    if not info.get("ok"):
+        raise RuntimeError("Download failed.")
+    return {"kind": "track", "title": info["title"], "artist": info["artist"],
+            "ok": 1, "total": 1, "path": None, "lidarr_album_id": None}