fix: v1.9.8 — expired torrent reimport failed for torrent-file additions

Root cause: _handle_expired_reimport only reimported if the torrent had a
magnet link stored in the DB. Torrents added via .torrent file or torrent
URL (the majority when using Sonarr/Radarr or Jackett torrent_url) were
stored with magnet=NULL. On expiry these fell into the else branch and
were marked error: "Add magnet again to retry" — no automatic re-import.

AllDebrid accepts plain hash magnets (magnet:?xt=urn:btih:<hash>) with
identical behaviour to full magnet links. The infohash is always stored
in the DB (extracted from the .torrent file or returned by AllDebrid on
upload).

Fix: if no magnet is stored, synthesize one from the infohash:
  magnet:?xt=urn:btih:<hash>&dn=<url-encoded-name>

Three cases are now handled:
  1. magnet stored → use it directly (existing behaviour, unchanged)
  2. no magnet, hash stored (SHA-1 40 chars or SHA-256 64 chars)
     → synthesize magnet:?xt=urn:btih:<hash>&dn=<name>, reimport
  3. no magnet, no hash → mark error with clear message (unchanged)

The synthesized magnet is only used for the re-upload call; it is not
written back to the DB (the original NULL is preserved).

292/292 tests passing

Author: claude

VERSION

@@ -1 +1 @@
-1.9.7
+1.9.8

backend/services/manager_v2.py

@@ -1434,6 +1434,24 @@ async def _apply_provider_update(self, row: Dict, magnet: Dict, normalized: Dict
             # magnet, silently re-upload it so the user does not need to intervene.
             magnet_link = str(row.get("magnet") or "").strip()
             torrent_name = str(row.get("name") or f"torrent {row['id']}")
+
+            # If no magnet was stored (e.g. added via .torrent file or torrent URL),
+            # synthesize a bare magnet from the infohash.  AllDebrid accepts
+            # magnet:?xt=urn:btih:<hash> identically to full magnet links.
+            if not magnet_link:
+                stored_hash = str(row.get("hash") or "").strip().lower()
+                if stored_hash and len(stored_hash) in (40, 64):  # SHA-1 or SHA-256 btih
+                    import urllib.parse as _up
+                    magnet_link = (
+                        f"magnet:?xt=urn:btih:{stored_hash}"
+                        f"&dn={_up.quote(torrent_name[:120])}"
+                    )
+                    logger.info(
+                        "expired_reimport: no magnet stored for torrent %s — "
+                        "synthesized from hash %s",
+                        row["id"], stored_hash[:16],
+                    )
+
             if magnet_link:
                 logger.warning(
                     "Magnet expired on AllDebrid (torrent %s '%s') — reimporting",