fix(app): show unread for pending questions - #34684

Summary

• Treat pending session questions as tab attention state, same as permissions
• Show unread indicator and suppress loading while a question is waiting for user input
• Includes child/subagent questions via sessionQuestionRequest

Tests

• bun typecheck (packages/app)
• git push pre-push hook: bun turbo typecheck

Note

• Targeted composer-state test currently fails before running tests with Solid Router client-only server-side API error; unrelated to this change.