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/src/nisse_dev/loop/tools.py

@@ -55,9 +55,19 @@ FINISH_MILESTONE = _tool(
     "your fix to the PR. Ends your turn; you continue when the PR is "
     "reviewed or merged.",
     summary="What the milestone did and how it was verified, for the PR.",
+    title="A short title for the PR (ignored when pushing a review fix).",
+)
+WAIT_FOR_REVIEW = _tool(
+    "wait_for_review",
+    "Nothing more to do until the operator reviews or merges the PR (you "
+    "can't merge it yourself): say so and wait. You continue when there's a "
+    "new comment, or when it merges or closes.",
+    note="What you're waiting on, for the operator.",
 )
 
-WAITING = frozenset({"restate", "ask_human", "close_item", "finish_milestone"})
+WAITING = frozenset(
+    {"restate", "ask_human", "close_item", "finish_milestone", "wait_for_review"}
+)
 
 
 def names(tools: list[dict[str, Any]]) -> set[str]: