feat(dependencies): update database engine dependencies to support async operations

python/ebook_search/api/routes/search.py

@@ -13,7 +13,6 @@ from fastapi.responses import HTMLResponse
 from python.ebook_search.answer import answer_query
 from python.ebook_search.api.dependencies import (  # noqa: TC001 FastAPI resolves these annotated dependencies at runtime
     AppConfig,
-    AppEngine,
     AppHttpClient,
 )
 from python.ebook_search.api.web import error_response, templates
@@ -25,6 +24,7 @@ from python.ebook_search.guardrails import (
 )
 from python.ebook_search.search import SearchResponse, search_ebooks
 from python.ebook_search.timing import runtime_step_from_start
+from python.fastapi_tools import AppAsyncEngine  # noqa: TC001 FastAPI resolves this annotated dependency at runtime
 
 if TYPE_CHECKING:
     import httpx
@@ -76,7 +76,7 @@ async def build_answer(
 async def search(
     request: Request,
     config: AppConfig,
-    engine: AppEngine,
+    engine: AppAsyncEngine,
     client: AppHttpClient,
     query: Annotated[str, Form()],
     *,