M7.4: nisse-dev answers a peer

Anyone's comment on an item's PR but an operator's (and its own) is a
peer's point (D5, L11): kept on the item with an id, in the transcript as
a `peer` message labelled with its author, and never an instruction. The
driver answers each with answer_peer, inline on its line or quoting it,
or skips it with skip_peer and a recorded reason. A run going back to
waiting with points open is reminded once; then the harness lists them
on the PR. A peer's comment wakes the item; a wake by peers alone goes
back to the same wait quietly, with one line in the thread. The
operator's inline comments are now answered inline too.

Also corrects ci.yml's header: a push to main runs no end-to-end tests.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-dev/src/nisse_dev/loop/tools.py

@@ -52,6 +52,25 @@ WAIT_FOR_REVIEW = _tool(
     note="What you're waiting on, for the operator.",
 )
 
+# A peer's points on the PR (D5): anyone's comment but an operator's. Not
+# waiting tools: the run goes on.
+ANSWER_PEER = _tool(
+    "answer_peer",
+    "Answer one of a peer's points on the PR, where it was made: what you "
+    "changed (or will change in this push), or why you disagree. Posted at "
+    "once.",
+    point="The point's id, like P2.",
+    reply="Your answer, in plain language.",
+)
+SKIP_PEER = _tool(
+    "skip_peer",
+    "A peer's point needs no reply (an automated notice, say): mark it "
+    "answered without posting anything. The reason is recorded for the "
+    "operator.",
+    point="The point's id, like P2.",
+    reason="Why it needs no reply.",
+)
+
 TOOLCHAIN_STEP = _tool(
     "toolchain_step",
     "The work needs a toolchain change (a new tool, library or version): a "