fix: tool registry emits Anthropic schema, question lifecycle cleanup

- Tool.to_schema() emits input_schema (Anthropic Messages API) instead
  of OpenAI-style parameters
- QuestionManager: remove questions from _pending on answer and timeout,
  reject double answers, add list_pending()
- core/skills/__init__.py so skills are importable as a package
- revert optional-import fallbacks in logger/message_bus: nats-py and
  loguru are hard requirements, a broken install should fail loudly
- tests for wait_for_answer happy path and timeout cleanup

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012AJLYcbTHCe45fyFnMfEin

tests/test_tool_registry.py

@@ -27,7 +27,8 @@ async def test_tool_registry_registration_and_execution():
     schemas = registry.get_schemas()
     assert len(schemas) == 1
     assert schemas[0]["name"] == "test_tool"
-    assert "order_id" in schemas[0]["parameters"]["properties"]
+    assert "order_id" in schemas[0]["input_schema"]["properties"]
+    assert "parameters" not in schemas[0]  # Anthropic shape, not OpenAI
 
     result = await registry.execute_tool("test_tool", order_id="ORD-100")
     assert result == {"order": "ORD-100", "items": 1}
@@ -50,6 +51,32 @@ async def test_question_manager_flow():
     assert q.options[0].badge == "12 AM–9 AM"
     assert not q.answered
 
-    qm.answer_question(q.question_id, "morning")
+    assert qm.list_pending() == [q]
+    assert qm.answer_question(q.question_id, "morning") is True
     assert q.answered is True
     assert q.answer == "morning"
+    assert qm.get_pending(q.question_id) is None  # cleaned up, not leaked
+    assert qm.answer_question(q.question_id, "afternoon") is False  # double-answer rejected
+
+
+@pytest.mark.asyncio
+async def test_question_manager_wait_and_answer():
+    qm = QuestionManager()
+    q = qm.create_question(prompt="Reassign?", options=["yes", "no"], allow_custom_input=False)
+
+    async def operator():
+        await asyncio.sleep(0.01)
+        qm.answer_question(q.question_id, "yes")
+
+    asyncio.create_task(operator())
+    assert await qm.wait_for_answer(q, timeout_s=1.0) == "yes"
+    assert qm.get_pending(q.question_id) is None
+
+
+@pytest.mark.asyncio
+async def test_question_manager_timeout_cleans_up():
+    qm = QuestionManager()
+    q = qm.create_question(prompt="Reassign?", options=["yes", "no"])
+    with pytest.raises(TimeoutError):
+        await qm.wait_for_answer(q, timeout_s=0.01)
+    assert qm.get_pending(q.question_id) is None