fix(app_controller): clear project-switch state in _handle_reset_session

When a prior test in the tier-3-live_gui batch leaves a _do_project_switch
background thread running, the next test's btn_project_new_automated click
sees _project_switch_in_progress=True (from the prior thread) and queues
the new path via _project_switch_pending_path. The queued switch is never
actually submitted to the io_pool, so is_project_stale() stays True and
AI ops (_handle_generate_send) bail with 'project switch in progress;
AI ops disabled'.

Fix: _handle_reset_session now also clears _project_switch_in_progress,
_project_switch_pending_path, and _project_switch_error (under the
existing _project_switch_lock). This way, even if the prior background
thread is still running, the controller reports an idle state and the
new switch can be submitted normally.

Also:
- src/api_hook_client.py: reverted wait_for_project_switch to require
  in_progress=False (was relaxed to return on queued path, which misled
  the caller into thinking the switch was done)
- tests/test_handle_reset_session_clears_project.py: new test
  test_handle_reset_session_clears_project_switch_state asserts
  is_project_stale() returns False after reset
- tests/test_api_hook_client_wait_for_project_switch.py: updated
  test_wait_for_project_switch_does_not_return_on_queued (in_progress
  + matching path should keep waiting, not return early)
- tests/test_live_workflow.py: added pre-wait for any in-flight switch
  before doing btn_reset (so the test waits up to 60s for the prior
  switch to complete if needed)
- conductor/todos/TODO_test_full_live_workflow.md: updated Task 4 with
  the deeper hang analysis and recommended fix

Known follow-up: test_full_live_workflow still hangs in tier-3 batch
even with this fix, because the new _do_project_switch itself is hung
in the io_pool (likely saturation from prior sims' AI discussion turn
workers). Deeper investigation required.

src/app_controller.py

@@ -3276,6 +3276,13 @@ class AppController:
    Path(self.active_project_path).stem if self.active_project_path else "unnamed"
   )
   self.project_paths = []
+  # Clear project-switch state machine so a hung switch from a prior test
+  # does not block the next session. (is_project_stale() must return False
+  # for the next click to actually submit a new switch.)
+  with self._project_switch_lock:
+   self._project_switch_in_progress = False
+   self._project_switch_pending_path = None
+   self._project_switch_error = None
   self.ai_status = "session reset"
   self.ai_response = ""
   self.ui_ai_input = ""