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

tests/integration/test_planning_live.py

@@ -27,7 +27,7 @@ def test_live_planning_turn_returns_a_tool_action(
     model = live_model
     roles = RoleMap(executor=model, planner=model, helper=model, expert=model)
     store = StateStore(tmp_path / "state.db", oplog=OpLog("nisse-dev", io.StringIO()))
-    store.append_event(
+    store.transcript("t", "operator").append(
         UserMessage(
             text=(
                 "Project 'hello-cli': a Python script that prints a greeting. "
@@ -36,12 +36,12 @@ def test_live_planning_turn_returns_a_tool_action(
             source="live-test",
         )
     )
-    agent = LLMPlanningAgent(litellm, store, roles)
+    agent = LLMPlanningAgent(litellm, roles)
 
-    action = agent.plan("arch", "hello-cli")
+    action = agent.plan(store.transcript("t", "planner"), "arch", "hello-cli")
 
     assert isinstance(action, SubmitPlan | AskHuman)
     text = action.content if isinstance(action, SubmitPlan) else action.question
     assert text.strip(), "tool call carried empty content"
     # The turn must be durable regardless of what the model said (L8/L7).
-    assert len(store.read_events()) > 1
+    assert len(store.transcript("t", "planner").read()) > 1