fix(server): annotate the binding page rows for SQLAlchemy 2.1

SQLAlchemy 2.1.0 no longer lets mypy infer the element type through
`result.scalars().all()`, so CI fails typecheck with var-annotated on a line
that is unchanged. The locked 2.0.51 still infers it, which is why this only
appears in CI. Annotate the local explicitly; it holds under both versions.

Author: jjeonsplunk

server/src/agent_control_server/services/control_bindings.py

@@ -279,7 +279,7 @@ def _apply_filters(stmt):  # type: ignore[no-untyped-def]
         if cursor is not None:
             page_stmt = page_stmt.where(ControlBinding.id < cursor)
         result = await self._db.execute(page_stmt.limit(limit + 1))
-        rows = list(result.scalars().all())
+        rows: list[ControlBinding] = list(result.scalars().all())
         has_more = len(rows) > limit
         if has_more:
             rows = rows[:limit]