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_properties.py

@@ -76,6 +76,8 @@ class PolicyModel:
             return [call("ask_human", question=f"question {self.n}?")]
         if roll < 0.12:
             return [ToolCall(call_id=f"p{self.n}", tool="nonsense", arguments={})]
+        if "reply" in offered and "propose_work" not in offered:
+            return [call("reply", text=f"because {self.n}")]  # a question run
         if "reply" in offered:  # a conversation: talk, or propose work
             if self.rng.random() < 0.1:
                 return [
@@ -99,7 +101,7 @@ class PolicyModel:
         if "restate" not in offered and "finish_milestone" not in offered:
             return [call("ask_human", question=f"talk first {self.n}?")]  # discuss
         if "finish_milestone" not in offered:
-            return [call("restate", text=f"restatement {self.n}")]
+            return [call("restate", text=f"restatement {self.n}", changed=f"c{self.n}")]
         if "delegate" in offered and self.rng.random() < 0.1:
             return [call("delegate", task=f"help {self.n}")]
         if "wait_for_review" in offered and self.rng.random() < 0.2:
@@ -248,7 +250,7 @@ class Walk:
         forge: Forge = self.worlds[project]["forge"]
         if item and loop:
             weights.update({"go": 3, "answer": 2, "abandon": 1, "go-stale": 1})
-            weights.update({"plain-yes": 2, "wait": 2})
+            weights.update({"plain-yes": 2, "wait": 2, "question": 2})
             if loop.new_project:
                 weights.update({"done": 2})
             if item.scope != "general":  # conversations aren't named by number
@@ -264,6 +266,28 @@ class Walk:
         elif action == "done" and loop:
             # The operator says a new project is ready; no entry was added.
             self.transport.receive(DON, "done", thread=loop.thread)
+        elif action == "question" and loop:
+            # L5: a question never changes the item it's asked about.
+            before = (item.position, loop.wait, loop.rev, loop.pr, loop.branch)
+            self.transport.receive(DON, f"why {len(self.steps)}?", thread=loop.thread)
+            after_item = self.world["store"].work_item(item.id)
+            after = loop_of(after_item)
+            if (
+                item.scope != "general"
+                and item.position == WAITING
+                and loop.wait in (GO_AHEAD, ANSWER, MERGE)
+            ):
+                now = (
+                    after_item.position,
+                    after.wait,
+                    after.rev,
+                    after.pr,
+                    after.branch,
+                )
+                assert now == before, (
+                    f"questions_change_nothing: {before} -> {now}: "
+                    f"seed {self.seed}, steps {self.steps}"
+                )
         elif action == "chat":
             # A top-level message: a conversation of its own (L1, L5).
             self.transport.receive(DON, f"thinking aloud {len(self.steps)}")