Put work items in the state store, and bind the log to them (M1.1)

Development Plan M1.1, as discussed.

- Schema v4: a work_items table (id, scope, title, status, outcome,
  position, data) and an agent row whose active_item points at one
  (NULL: idle). Canonical events and intents carry their work item, and
  events their actor. Older stores are refused with a clear message:
  there was no production data, so no migration (the mechanism stays).
- The log is reached through a Transcript bound to one work item and
  one actor: store.transcript(item, actor) reads only that item and
  writes with both. The planner, executor, delegation and expert desk
  get one per call from the orchestrator instead of holding the store,
  so a component can neither read another task's events (the planner
  read every earlier task's, #78) nor write without attribution.
  store.all_events() is kept for readers that span items (evaluation
  capture, dumps). Intents are begun through the transcript or with
  work_item=, so each belongs to its item.
- The orchestrator opens a work item on 'use', closes it with its
  outcome (completed or abandoned), and carries what the operator said
  while idle into the new item as copies with their origin, so a task
  sent before 'use' is still planned from (D1). control.py keeps its
  state machine through get_state()/transition(), now over the active
  work item, until M2.6 retires it.
- nisse_dev.dump shows work items and each event's item and actor.

Tests: test_work_items.py (scoping, attribution, intent ownership,
restart, outcomes, carried messages, a second task never seeing the
first); the suites updated for the per-call transcript.

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/expert.py

@@ -33,7 +33,7 @@ from nisse_dev.canonical import (
     UserMessage,
 )
 from nisse_dev.llm import LLMClient, LLMError, RoleMap
-from nisse_dev.state import StateStore
+from nisse_dev.state import Transcript
 
 EXPERT_ROLE = "expert"
 DEFAULT_BUDGET = 3
@@ -97,32 +97,34 @@ class ExpertDesk:
     def __init__(
         self,
         client: LLMClient,
-        store: StateStore,
         roles: RoleMap,
         *,
         budget: int = DEFAULT_BUDGET,
     ) -> None:
         self._client = client
-        self._store = store
         self._roles = roles
         self._budget = budget
 
-    def consults_used(self, since_event_id: int = 0) -> int:
+    def consults_used(self, transcript: Transcript, since_event_id: int = 0) -> int:
         return sum(
             1
-            for e in self._store.read_events(after=since_event_id)
+            for e in transcript.read(after=since_event_id)
             if isinstance(e.event, DelegationStarted) and e.event.role == EXPERT_ROLE
         )
 
-    def ask(self, question: str, *, since_event_id: int = 0) -> ExpertAnswer:
-        used = self.consults_used(since_event_id)
+    def ask(
+        self, transcript: Transcript, question: str, *, since_event_id: int = 0
+    ) -> ExpertAnswer:
+        """The consult is recorded in the work item's transcript, as the
+        expert, and the budget counts that work item's consults (L9)."""
+        used = self.consults_used(transcript, since_event_id)
         if used >= self._budget:
             raise BudgetExhausted(
                 f"consult budget of {self._budget} is spent for this task "
                 f"({used} used); escalate or ask the operator instead"
             )
         model = self._roles.resolve(EXPERT_ROLE)
-        self._store.append_event(
+        transcript.append(
             DelegationStarted(
                 brief=question,
                 role=EXPERT_ROLE,
@@ -131,7 +133,7 @@ class ExpertDesk:
             )
         )
         answer, note = self._answer(question, model)
-        self._store.append_event(
+        transcript.append(
             DelegationCompleted(
                 handback=answer.render() if answer else note,
                 artifacts=[],