fix(backend): use background task for startup to avoid blocking server

Change program.startup() to run via asyncio.create_task() so uvicorn
accepts connections immediately while downloader check runs in background.
Also add .claude/ project settings.

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

.claude/settings.local.json

@@ -0,0 +1,87 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(git -C /Users/estrella/Developer/AutoBangumi/Auto_Bangumi log --oneline -10)",
+      "Bash(git checkout:*)",
+      "Bash(python -m pytest:*)",
+      "Bash(python:*)",
+      "Bash(uv init:*)",
+      "Bash(uv sync:*)",
+      "Bash(uv run pytest:*)",
+      "Skill(feature-dev:feature-dev)",
+      "Bash(uv pip install:*)",
+      "Bash(uv run python:*)",
+      "Bash(curl:*)",
+      "Bash(pkill:*)",
+      "Bash(uv pip show:*)",
+      "Bash(uv pip list:*)",
+      "Bash(uv lock:*)",
+      "Bash(lsof:*)",
+      "Bash(kill:*)",
+      "Bash(VITE_API_URL=http://localhost:18080 pnpm dev:*)",
+      "Bash(pnpm dev:*)",
+      "Bash(pnpm add:*)",
+      "Bash(git add:*)",
+      "Bash(git commit:*)",
+      "Skill(planning-with-files)",
+      "Bash(../.venv/bin/python -m pytest test/test_database.py -v)",
+      "Bash(.venv/bin/python:*)",
+      "Bash(ruff check:*)",
+      "Bash(ls:*)",
+      "Bash(/Users/estrella/Developer/AutoBangumi/Auto_Bangumi/backend/.venv/bin/python:*)",
+      "Bash(uv run ruff check:*)",
+      "Bash(git rm:*)",
+      "Bash(git push:*)",
+      "Bash(gh pr create:*)",
+      "Bash(gh pr checks:*)",
+      "Bash(gh run view:*)",
+      "Bash(git ls-tree:*)",
+      "Bash(while read f)",
+      "Bash(do git show \"HEAD:$f\")",
+      "Bash(done)",
+      "Bash(git reset:*)",
+      "Skill(ui-ux-pro-max)",
+      "Bash(tree:*)",
+      "Bash(git stash:*)",
+      "Bash(python3:*)",
+      "Bash(pnpm build:*)",
+      "Bash(pnpm install:*)",
+      "Bash(uv venv:*)",
+      "Bash(../.venv/bin/python:*)",
+      "Bash(xargs:*)",
+      "Skill(agent-browser)",
+      "Bash(agent-browser open:*)",
+      "Bash(agent-browser screenshot:*)",
+      "Bash(agent-browser snapshot:*)",
+      "Bash(agent-browser eval \"JSON.stringify\\(window.__consoleErrors || ''no errors captured''\\)\")",
+      "Bash(agent-browser eval:*)",
+      "Bash(agent-browser close:*)",
+      "Bash(agent-browser reload:*)",
+      "Bash(agent-browser fill:*)",
+      "Bash(agent-browser click:*)",
+      "Skill(commit-commands:commit)",
+      "Bash(gh api:*)",
+      "Bash(git fetch:*)",
+      "Bash(git rebase:*)",
+      "Bash(grep:*)",
+      "Bash(git merge:*)",
+      "Bash(agent-browser scroll:*)",
+      "Bash(agent-browser find text \"Passkey Settings\" click)",
+      "Bash(agent-browser find:*)",
+      "Bash(agent-browser find text \"添加\" click)",
+      "Bash(npx vue-tsc:*)",
+      "Bash(npx vite build:*)",
+      "WebSearch",
+      "WebFetch(domain:bangumi.github.io)",
+      "WebFetch(domain:raw.githubusercontent.com)",
+      "WebFetch(domain:api.bgm.tv)",
+      "Bash(__NEW_LINE_e2219f405dac932c__ echo \"\")",
+      "Bash(__NEW_LINE_7c1bb4605ef4ad2a__ echo \"\")",
+      "Bash(source ../.venv/bin/activate)",
+      "Bash(source:*)",
+      "Bash(npx vite:*)",
+      "Bash(agent-browser press:*)",
+      "Bash(agent-browser get:*)"
+    ]
+  }
+}

backend/src/module/api/program.py

@@ -1,3 +1,4 @@
+import asyncio
 import logging
 import os
 import signal
@@ -19,7 +20,7 @@ router = APIRouter(tags=["program"])
 
 @router.on_event("startup")
 async def startup():
-    await program.startup()
+    asyncio.create_task(program.startup())
 
 
 @router.on_event("shutdown")