feat(auth): implement authentication endpoints and JWT handling

app/main.py

@@ -1,17 +1,25 @@
 from contextlib import asynccontextmanager
 
-from fastapi import FastAPI
-
+from api.auth.router import router as auth_router
 from api.proxy.router import router as proxy_router
-from db.proxy import ensure_proxy_indexes
+from core.config import settings
 from core.mongodb import close_mongodb, init_mongodb
 from core.redis import close_redis, init_redis
+from core.security import hash_password
+from db.auth import ensure_auth_indexes, ensure_single_account
+from db.proxy import ensure_proxy_indexes
+from fastapi import FastAPI
 
 
 @asynccontextmanager
 async def lifespan(_: FastAPI):
     await init_mongodb()
     await init_redis()
+    await ensure_auth_indexes()
+    await ensure_single_account(
+        username=settings.AUTH_USERNAME,
+        password_hash=hash_password(settings.AUTH_PASSWORD),
+    )
     await ensure_proxy_indexes()
     try:
         yield
@@ -24,6 +32,7 @@ app = FastAPI(
     lifespan=lifespan,
 )
 
+app.include_router(auth_router)
 app.include_router(proxy_router)