Conversation on the new loop (M2.7)

- Questions never change state (L5, #77): a message ending in "?" to a
  waiting project item starts a question run (reply and look-only tools,
  an instruction to change nothing), and the item goes back to the very
  wait it was in: a restatement up stays up and a go binds to it; the
  agent's own question stays open.
- Explanations: a restatement gives its reasons and the main alternative;
  a revision says what changed (restate(changed), sent back without it);
  a milestone's summary says what was done, verified and left open.
- Progress in prose (#42): the driver's and a helper's own words for a
  turn are posted, trimmed, at most once a minute per item; `details`
  shows the last tool calls; a message arriving mid-run is acknowledged at
  once ("Noted; ...").
- CI: the e2e job's comments and the plan no longer claim a newer push
  cancels the run it supersedes (Gitea here doesn't); the concurrency
  block goes.

Tests: conversation unit tests (questions in a go-ahead and an answer wait,
an unanswerable question, revisions, progress rate and trimming, details,
mid-run notes), the helper's progress, the walk asking questions in every
state with a questions_change_nothing property (routing questions the old
way fails 32 of 48 seeds), and an e2e question while a restatement is up.

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_help.py

@@ -301,3 +301,26 @@ def test_a_delegation_cut_off_by_a_crash_is_discarded_at_boot(
     ]
     assert any("cut off by a restart and discarded" in f for f in facts)
     assert git
+
+
+def test_a_helpers_progress_is_posted(world: dict[str, Any]) -> None:
+    helper = Spy(
+        [
+            AssistantText(text="Writing helped.py with the constant.", model="hlp"),
+            call("write_file", path="helped.py", content="H = 1\n"),
+        ],
+        [hand_back()],
+    )
+    model = ScriptedModel(
+        RESTATE,
+        [
+            call("start_milestone", name="words"),
+            call("delegate", task="write helped.py"),
+            call("ask_human", question="done?"),
+        ],
+    )
+    agent, transport = loop_agent(world, model, helpers=helpers(helper))
+    agent.intake()
+    say(transport, world, "go")
+    said = [m.text for m in transport.outbound]
+    assert "helper: Writing helped.py with the constant." in said