fix: improve rename reliability and add torrent tagging API

- Fix qBittorrent rename verification (verify file actually renamed)
- Add pending rename cooldown to prevent spam when rename delayed
- Add torrent tagging API for accurate offset lookup
- Add auto calendar refresh every 24 hours
- Fix frontend error handling (don't logout on server errors)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/module/api/downloader.py

@@ -1,9 +1,14 @@
+import logging
+
 from fastapi import APIRouter, Depends
 from pydantic import BaseModel
 
+from module.database import Database
 from module.downloader import DownloadClient
 from module.security.api import get_current_user
 
+logger = logging.getLogger(__name__)
+
 router = APIRouter(prefix="/downloader", tags=["downloader"])
 
 
@@ -16,6 +21,12 @@ class TorrentDeleteRequest(BaseModel):
     delete_files: bool = False
 
 
+class TorrentTagRequest(BaseModel):
+    """Request to tag a torrent with a bangumi ID."""
+    hash: str
+    bangumi_id: int
+
+
 @router.get("/torrents", dependencies=[Depends(get_current_user)])
 async def get_torrents():
     async with DownloadClient() as client:
@@ -44,3 +55,91 @@ async def delete_torrents(req: TorrentDeleteRequest):
     async with DownloadClient() as client:
         await client.delete_torrent(hashes, delete_files=req.delete_files)
     return {"msg_en": "Torrents deleted", "msg_zh": "种子已删除"}
+
+
+@router.post("/torrents/tag", dependencies=[Depends(get_current_user)])
+async def tag_torrent(req: TorrentTagRequest):
+    """Tag a torrent with a bangumi ID for accurate offset lookup.
+
+    This adds the 'ab:ID' tag to the torrent in qBittorrent, which allows
+    the renamer to look up the correct episode/season offset.
+    """
+    # Verify bangumi exists
+    with Database() as db:
+        bangumi = db.bangumi.search_id(req.bangumi_id)
+        if not bangumi:
+            return {
+                "status": False,
+                "msg_en": f"Bangumi {req.bangumi_id} not found",
+                "msg_zh": f"未找到番剧 {req.bangumi_id}",
+            }
+
+    tag = f"ab:{req.bangumi_id}"
+    async with DownloadClient() as client:
+        await client.add_tag(req.hash, tag)
+
+    return {
+        "status": True,
+        "msg_en": f"Tagged torrent with {tag}",
+        "msg_zh": f"已为种子添加标签 {tag}",
+    }
+
+
+@router.post("/torrents/tag/auto", dependencies=[Depends(get_current_user)])
+async def auto_tag_torrents():
+    """Auto-tag all untagged Bangumi torrents based on name/path matching.
+
+    This helps fix torrents that were added before tagging was implemented.
+    Returns the number of torrents tagged and any that couldn't be matched.
+    """
+    tagged_count = 0
+    unmatched = []
+
+    async with DownloadClient() as client:
+        # Get all Bangumi torrents
+        torrents = await client.get_torrent_info(category="Bangumi", status_filter=None)
+
+        with Database() as db:
+            for torrent in torrents:
+                torrent_hash = torrent["hash"]
+                torrent_name = torrent["name"]
+                save_path = torrent["save_path"]
+                tags = torrent.get("tags", "")
+
+                # Skip if already has ab: tag
+                if "ab:" in tags:
+                    continue
+
+                # Try to match bangumi
+                bangumi = None
+
+                # First try by torrent name
+                bangumi = db.bangumi.match_torrent(torrent_name)
+
+                # Then try by save_path
+                if not bangumi:
+                    bangumi = db.bangumi.match_by_save_path(save_path)
+
+                if bangumi and not bangumi.deleted:
+                    tag = f"ab:{bangumi.id}"
+                    await client.add_tag(torrent_hash, tag)
+                    tagged_count += 1
+                    logger.info(
+                        f"[AutoTag] Tagged '{torrent_name[:50]}...' with {tag} "
+                        f"(matched: {bangumi.official_title})"
+                    )
+                else:
+                    unmatched.append({
+                        "hash": torrent_hash,
+                        "name": torrent_name,
+                        "save_path": save_path,
+                    })
+
+    return {
+        "status": True,
+        "tagged_count": tagged_count,
+        "unmatched_count": len(unmatched),
+        "unmatched": unmatched[:10],  # Return first 10 unmatched for debugging
+        "msg_en": f"Tagged {tagged_count} torrents, {len(unmatched)} could not be matched",
+        "msg_zh": f"已标记 {tagged_count} 个种子，{len(unmatched)} 个无法匹配",
+    }