Fix SyntaxError: reorder delete_passkey params

Move `request: Request` (no default) before parameters with defaults
to fix 'parameter without default follows parameter with default'.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/routers/passkeys.py

@@ -403,9 +403,9 @@ async def list_passkeys(
 
 @router.delete("/{credential_id}")
 async def delete_passkey(
+    request: Request,
     credential_id: int = Path(ge=1, le=2147483647),
     data: PasskeyDeleteRequest = ...,
-    request: Request,
     db: AsyncSession = Depends(get_db),
     current_user: User = Depends(get_current_user),
 ):