Speculative fix for a sometimes speech crash bug.

tests/unit/test_output_manager.py

@@ -26,6 +26,14 @@ def build_output_manager():
             "SoundDriver": sound_driver,
             "SpeechDriver": speech_driver,
             "DebugManager": Mock(write_debug_out=Mock()),
+            "TextManager": Mock(
+                replace_head_lines=Mock(side_effect=lambda text: text)
+            ),
+            "PunctuationManager": Mock(
+                proceed_punctuation=Mock(
+                    side_effect=lambda text, _ignore_punctuation: text
+                )
+            ),
         },
     }
     return output_manager, sound_driver, speech_driver
@@ -122,6 +130,40 @@ def test_interrupt_output_waits_only_briefly_for_slow_cancel():
         output_manager.interrupt_thread.join(timeout=1.0)
 
 
+@pytest.mark.unit
+def test_cancel_speech_skips_when_speech_driver_is_busy():
+    output_manager, _sound_driver, speech_driver = build_output_manager()
+    output_manager.speech_driver_lock_timeout = 0.01
+    output_manager.speech_driver_lock.acquire()
+
+    try:
+        start_time = time.monotonic()
+        output_manager.cancel_speech()
+        elapsed = time.monotonic() - start_time
+    finally:
+        output_manager.speech_driver_lock.release()
+
+    assert elapsed < 0.2
+    speech_driver.cancel.assert_not_called()
+
+
+@pytest.mark.unit
+def test_speak_text_drops_speech_when_cancel_holds_driver_lock():
+    output_manager, _sound_driver, speech_driver = build_output_manager()
+    output_manager.speech_driver_lock_timeout = 0.01
+    output_manager.speech_driver_lock.acquire()
+
+    try:
+        start_time = time.monotonic()
+        output_manager.speak_text("hello", interrupt=False, flush=False)
+        elapsed = time.monotonic() - start_time
+    finally:
+        output_manager.speech_driver_lock.release()
+
+    assert elapsed < 0.2
+    speech_driver.speak.assert_not_called()
+
+
 @pytest.mark.unit
 def test_key_interrupt_command_uses_nonblocking_interrupt():
     module = load_key_interrupt_module()