fix(server): incorrect list condition (#13005)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Improved session filtering to use the correct criteria when querying
sessions, ensuring more accurate results based on the action parameter.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/models/copilot-session.ts

@@ -310,7 +310,7 @@ export class CopilotSessionModel extends BaseModel {
         id: getEqCond(sessionId),
         deletedAt: null,
         pinned: getEqCond(options.pinned),
-        prompt: getNullCond(fork, ret => ({ action: ret })),
+        prompt: getNullCond(action, ret => ({ action: ret })),
         parentSessionId: getNullCond(fork),
       },
     ];