ROOT CAUSE: 3 mismatched names in the empty-context warning path:
1. _handle_generate_send set self.show_empty_context_warning_modal = True
but render_empty_context_modal checks self.show_empty_context_modal.
The modal never opened.
2. _handle_generate_send / _handle_md_only never set
self._pending_generation_action, so the modal's 'Proceed Anyway'
button always saw None and dispatched nothing.
3. After Proceed Anyway, _pending_generation_action was never reset,
so subsequent empty-context calls would dispatch the wrong action.
FIX:
- gui_2.py:494,501: show_empty_context_warning_modal -> show_empty_context_modal
- gui_2.py:494,501: set _pending_generation_action before showing modal
- gui_2.py:5385: reset _pending_generation_action = None after dispatch
Tests: tests/test_gen_send_empty_context.py (5 cases) covers all 4 dispatch
paths (generate/md_only x proceed/skip) plus the happy path with context.
37/37 regression pass. No new ImGui scope errors (2 pre-existing unrelated).
