fix: use AsyncSession type hints in firmware_route for proper type checking

Import AsyncSession from sqlalchemy.ext.asyncio instead of Session from
sqlalchemy.orm, and update all endpoint type hints to reflect that the
get_db() dependency provides AsyncSession for async endpoints.

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

Author: code-root

backend/api/routes/firmware_route.py

@@ -20,7 +20,7 @@
 
 from fastapi import APIRouter, Depends, HTTPException, UploadFile, File
 from pydantic import BaseModel
-from sqlalchemy.orm import Session
+from sqlalchemy.ext.asyncio import AsyncSession
 from sqlalchemy import select
 
 from api.deps import get_current_user, get_db
@@ -156,7 +156,7 @@ async def get_firmware_sources(
 @router.post("/upload")
 async def upload_firmware_file(
     file: UploadFile = File(...),
-    db: Session = Depends(get_db),
+    db: AsyncSession = Depends(get_db),
     _user: User = Depends(get_current_user),
 ) -> FirmwareEntryResponse:
     """
@@ -327,7 +327,7 @@ async def list_available_packages(
 async def list_firmware_entries(
     model: Optional[str] = None,
     csc: Optional[str] = None,
-    db: Session = Depends(get_db),
+    db: AsyncSession = Depends(get_db),
     _user: User = Depends(get_current_user),
 ) -> List[FirmwareEntryResponse]:
     """
@@ -356,7 +356,7 @@ async def list_firmware_entries(
 @router.post("/entries")
 async def create_firmware_entry(
     req: FirmwareEntryCreate,
-    db: Session = Depends(get_db),
+    db: AsyncSession = Depends(get_db),
     _user: User = Depends(get_current_user),
 ) -> FirmwareEntryResponse:
     """
@@ -405,7 +405,7 @@ async def create_firmware_entry(
 async def update_firmware_entry(
     entry_id: int,
     req: FirmwareEntryUpdate,
-    db: Session = Depends(get_db),
+    db: AsyncSession = Depends(get_db),
     _user: User = Depends(get_current_user),
 ) -> FirmwareEntryResponse:
     """
@@ -435,7 +435,7 @@ async def update_firmware_entry(
 @router.delete("/entries/{entry_id}")
 async def delete_firmware_entry(
     entry_id: int,
-    db: Session = Depends(get_db),
+    db: AsyncSession = Depends(get_db),
     _user: User = Depends(get_current_user),
 ) -> Dict[str, Any]:
     """
@@ -458,7 +458,7 @@ async def delete_firmware_entry(
 
 @router.post("/sync")
 async def sync_firmware_entries(
-    db: Session = Depends(get_db),
+    db: AsyncSession = Depends(get_db),
     _user: User = Depends(get_current_user),
 ) -> Dict[str, Any]:
     """