feat: fix search, poster serving, and add hover overlay UI for cards

- Fix search store exports to match component expectations (inputValue,
  bangumiList, onSearch) and transform data to SearchResult format
- Fix poster endpoint path check that incorrectly blocked all requests
- Add resolvePosterUrl utility to handle both external URLs and local paths
- Move tags into hover overlay on homepage cards and calendar cards
- Show title and tags on poster hover with dark semi-transparent styling
- Add downloader API, store, and page
- Update backend to async patterns and uv migration changes
- Remove .claude/settings.local.json from tracking

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

backend/src/module/api/__init__.py

@@ -3,6 +3,7 @@ from fastapi import APIRouter
 from .auth import router as auth_router
 from .bangumi import router as bangumi_router
 from .config import router as config_router
+from .downloader import router as downloader_router
 from .log import router as log_router
 from .passkey import router as passkey_router
 from .program import router as program_router
@@ -19,5 +20,6 @@ v1.include_router(log_router)
 v1.include_router(program_router)
 v1.include_router(bangumi_router)
 v1.include_router(config_router)
+v1.include_router(downloader_router)
 v1.include_router(rss_router)
 v1.include_router(search_router)