Respond to Copilot's lazy-start review: session metadata/history/usage do not
need a constructed AIAgent, so keep them on the no-wait session path. This
preserves the deferred startup model and avoids blocking simple session RPCs on
agent initialization.
Tests:
- python -m py_compile tui_gateway/server.py tui_gateway/entry.py
- cd ui-tui && npm run type-check && npm run build
- scripts/run_tests.sh tests/tui_gateway/test_protocol.py::test_sess_found tests/tools/test_code_execution_modes.py tests/tools/test_code_execution.py
- cd ui-tui && npm test -- --run src/__tests__/useSessionLifecycle.test.ts src/__tests__/useConfigSync.test.ts
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