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

.gitea/workflows/ci.yml

@@ -1,9 +1,11 @@
 name: CI
-# Three levels of testing:
+# Four levels of testing:
 #   - every PR: lint, unit tests (16 property walks), integration tests, and
 #     the smoke end-to-end tests (`smoke` marker);
-#   - a PR labelled e2e:full, a push to main and a manual run: all 48 walks
-#     and the whole end-to-end suite;
+#   - a PR labelled e2e:full and a manual run: all 48 walks and the whole
+#     end-to-end suite;
+#   - a push to main: all 48 walks, and no end-to-end tests (the PR ran
+#     the smoke ones, and the rest when labelled e2e:full);
 #   - a published release: the full set again before its image (release.yml).
 on:
   # Only main on push. A PR branch is already covered by the pull_request