Answer where asked, wait on a merge, and let the driver title PRs

From the new loop's first live run (sandbox #255, PR #256):
- A question asked on the PR is answered on the PR (an inline one quoted
  with its file and line, since the API can't reply in its thread), with
  a pointer in the item's Matrix thread; one asked in Matrix stays there.
- wait_for_review: when a review needs no change, or only the operator's
  merge is left, the item waits on the merge instead of on an answer.
- finish_milestone takes the PR's title from the driver.
The e2e test's merge waits out Gitea's brief 'try again later' after a
push.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

nisse-dev/tests/test_loop_properties.py

@@ -53,6 +53,8 @@ class PolicyModel:
             return [ToolCall(call_id=f"p{self.n}", tool="nonsense", arguments={})]
         if "finish_milestone" not in offered:
             return [call("restate", text=f"restatement {self.n}")]
+        if "wait_for_review" in offered and self.rng.random() < 0.2:
+            return [call("wait_for_review", note=f"waiting {self.n}")]
         merged = any("merged" in t for t in facts[-6:])
         if merged and self.rng.random() < 0.8:
             return [call("close_item", summary=f"done {self.n}")]