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_delegation_live.py

@@ -45,11 +45,13 @@ def build(
 def test_delegate_completes_a_scoped_subtask(
     tmp_path: Path, passthrough: AnthropicPassthroughClient, live_model: str
 ) -> None:
-    delegation, repo, _store = build(
+    delegation, repo, store = build(
         tmp_path, Caps(turns=12, wall_clock_s=300.0), passthrough, live_model
     )
 
-    result = delegation.run(brief=BRIEF, branch="live/delegation-1")
+    result = delegation.run(
+        store.transcript("t", "helper"), brief=BRIEF, branch="live/delegation-1"
+    )
 
     assert result.usable, f"delegation did not hand back: {result.status} {result.note}"
     assert (repo.root / "slugify.py").exists()
@@ -75,11 +77,13 @@ def test_a_cap_breach_discards_the_work(
 ) -> None:
     # One turn cannot finish the brief, so this exercises the abort path
     # against a real model rather than a scripted one.
-    delegation, repo, _ = build(
+    delegation, repo, store = build(
         tmp_path, Caps(turns=1, wall_clock_s=120.0), passthrough, live_model
     )
 
-    result = delegation.run(brief=BRIEF, branch="live/delegation-2")
+    result = delegation.run(
+        store.transcript("t", "helper"), brief=BRIEF, branch="live/delegation-2"
+    )
 
     assert not result.usable
     assert result.status == "capped"