Do not treat every channel reply as approval success

[padmanabh275]

Summary

• After request_approval parked with Choices: yes, no, any later message in the same channel thread called complete_waiting with success=True. no and unrelated text both authorised the gated action.
• The UI path already maps reject to success=False. Channel HITL did not.
• Channel resume now matches listed choices (casefold). no / reject / deny / cancel fail the gate. Unmatched or blank text leaves the wait handle in place so the message is a new request. Empty choices still accepts a non-empty free-text answer.

Test plan

• test_a_no_does_not_succeed_a_waiting_channel_approval failed before (succeeded vs failed) and passes after.
• test_unrelated_text_does_not_consume_a_waiting_channel_approval failed before (wait consumed) and passes after.
• test_a_reply_in_the_same_channel_thread_resumes_a_waiting_approval still passes for yes.
• pytest tests/test_channel_connections.py: 9 passed.

No .env, tokens, real messages, or API keys in this diff.

[theschoolofai]

Session 16 — graded ✅

Score: +100.

Every channel reply was treated as approval success, so an unrelated message could carry a run past a human gate. Exactly the failure Part 1 asks the assistant to prove it does not have.