Conversations on the new loop (M2.5, PR A)

- A top-level message that isn't a command is a conversation: an item in
  the `general` scope (L1), threaded under the operator's message, with
  `reply`, `ask_human` and `propose_work` and no workspace or execution.
  `general` is reserved as a project name.
- propose_work(project, title, summary) goes up as a revision for a
  go-ahead (or a plain yes). On go, under a file_issue intent (L8), the
  record issue is opened in that project, assigned to the agent and
  carrying the new item's ID; its item starts agreed, with the summary as
  its brief. Intake skips any issue carrying an ID (D1); boot adopts a
  filed issue or puts the proposal up again.
- A conversation closes after tuning.loop.general_idle_s (default a day);
  a reply in its thread then starts a new conversation that continues it.

Tests: conversation unit tests (threading, filing, the marker, an unknown
project, changes, idle close and continuation, a plain yes, both crash
cases, commands at top level); the walk with conversations, proposals and
idle time, and records_have_one_item / conversations_do_no_work; an e2e
conversation that becomes filed work.

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/items.py

@@ -20,6 +20,7 @@ CLOSED = "closed"
 GO_AHEAD = "go-ahead"  # a go on the restatement up (L3, D1)
 ANSWER = "answer"  # an answer to a question
 MERGE = "merge"  # the PR's review and merge (D4, D5)
+CHAT = "conversation"  # a conversation waits for the operator to say more (L5)
 
 
 @dataclass(frozen=True)
@@ -43,6 +44,14 @@ class Loop:
     labels: tuple[str, ...] = ()  # the issue's labels at intake: they steer (D1)
     grace_until: float = 0.0  # a `bug` restatement proceeds then, unanswered
     talked: bool = False  # the operator has spoken in the item's thread
+    # A conversation (`general`, L1): when it last heard or said anything,
+    # the conversation it continues, the work it turned into, and the work
+    # proposed for a go-ahead.
+    idle_since: float = 0.0
+    follows: str = ""
+    became: tuple[str, ...] = ()
+    proposal_project: str = ""
+    proposal_title: str = ""
     # Where the operator last spoke (D5: answer where asked): "" for the
     # Matrix thread, or the PR it came from, with the inline location and a
     # little of what they said, for quoting.
@@ -59,6 +68,7 @@ def loop_of(item: WorkItem) -> Loop:
     data["notes"] = tuple(data.get("notes", ()))
     data["blocked_by"] = tuple(data.get("blocked_by", ()))
     data["labels"] = tuple(data.get("labels", ()))
+    data["became"] = tuple(data.get("became", ()))
     return Loop(**data)
 
 
@@ -75,11 +85,13 @@ def save(
     )
 
 
-def item_for_thread(store: StateStore, thread: str) -> WorkItem | None:
-    for item in store.work_items("open"):
-        if loop_of(item).thread == thread:
-            return item
-    return None
+def item_for_thread(
+    store: StateStore, thread: str, status: str | None = "open"
+) -> WorkItem | None:
+    """The item whose conversation is ``thread``; the latest, when a closed
+    conversation's thread was picked up again."""
+    found = [i for i in store.work_items(status) if loop_of(i).thread == thread]
+    return found[-1] if found else None
 
 
 def item_for_issue(