Migrate the ini-file-read try/except in App._diag_layout_state (L591) to
the canonical Result[T] pattern:
- Extract _diag_layout_state_ini_text_result(app, ini_path) -> Result[str]
helper into new Phase 8 Property Setter / State Result Helpers region.
- The legacy _diag_layout_state method calls the helper and drains errors
to app._startup_timeline_errors (the Phase 2 drain plane for startup
callbacks).
- The original fallback behavior (early return on read failure, stderr
write for visibility) is preserved.
Tests:
- test_phase_8_l591_diag_layout_state_ini_text_result_success
- test_phase_8_l591_diag_layout_state_ini_text_result_failure
Audit: INTERNAL_BROAD_CATCH count in src/gui_2.py dropped from 2 to 1
(remaining: L896 _capture_workspace_profile, formerly L897 in inventory).
ed
d3b71a7304