M7.1: extract nisse-core

What isn't the dev agent's moves to nisse-core, unchanged in behaviour,
with its tests: canonical, render, render_anthropic, llm, catalog, probe,
context, views, state, reconcile, worker, cancel, dump, transport, matrix,
execution, testing, vault, memory, oplog, envfile and gitea (whole).

- nisse_core.state.StateStore holds the tables every agent has; an
  agent's subclass adds its tables (version, migrations), roles and
  views. nisse_dev.state.StateStore adds the build VM blocks (v5).
- views.project takes what each role is shown, rather than a fixed table.
- Vault takes the agent's name (agent=), for provenance.
- A test that nisse_core never imports an agent.
- The loop, config, git, delegation, expert, tools and evals stay in
  nisse-dev until nisse-ops has a loop to share.

Docs: the Development Plan marks M7.1 done and notes that Phase 6 waits on
the agent host and Terraform; Architecture Part L names the package.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-core/tests/test_worker.py

@@ -0,0 +1,83 @@
+import io
+import threading
+from pathlib import Path
+
+import pytest
+
+from nisse_core.oplog import OpLog
+from nisse_core.state import StateStore
+from nisse_core.worker import InlineWorker, SerialWorker
+
+
+@pytest.fixture
+def worker() -> SerialWorker:
+    w = SerialWorker()
+    w.start()
+    yield w
+    w.stop(timeout=5)
+
+
+def test_jobs_run_in_order_on_the_worker_thread(worker: SerialWorker) -> None:
+    seen: list[tuple[int, str]] = []
+    for n in range(3):
+        worker.submit(lambda n=n: seen.append((n, threading.current_thread().name)))
+    worker.call(lambda: None)  # drains everything queued before it
+
+    assert [n for n, _ in seen] == [0, 1, 2]
+    assert {name for _, name in seen} == {"nisse-worker"}
+
+
+def test_call_returns_the_result_and_raises_the_error(worker: SerialWorker) -> None:
+    assert worker.call(lambda: 42) == 42
+
+    def boom() -> None:
+        raise ValueError("bad job")
+
+    with pytest.raises(ValueError, match="bad job"):
+        worker.call(boom)
+
+
+def test_a_failed_job_is_reported_and_the_worker_carries_on() -> None:
+    errors: list[BaseException] = []
+    worker = SerialWorker(on_error=errors.append)
+    worker.start()
+
+    def boom() -> None:
+        raise RuntimeError("lost job")
+
+    worker.submit(boom)
+    assert worker.call(lambda: "still here") == "still here"
+    assert [str(e) for e in errors] == ["lost job"]
+    worker.stop(timeout=5)
+
+
+def test_call_from_the_worker_itself_runs_inline(worker: SerialWorker) -> None:
+    # Queueing behind itself would deadlock.
+    assert worker.call(lambda: worker.call(lambda: "nested")) == "nested"
+
+
+def test_the_store_is_usable_only_from_the_thread_that_owns_it(
+    worker: SerialWorker, tmp_path: Path
+) -> None:
+    store = worker.call(
+        lambda: StateStore(tmp_path / "state.db", oplog=OpLog("t", io.StringIO()))
+    )
+    assert worker.call(store.active_item) is None
+    # The tripwire the worker design keeps on: any other thread fails loudly.
+    with pytest.raises(Exception, match="same thread"):
+        store.active_item()
+    worker.call(store.close)
+
+
+def test_inline_worker_defers_a_job_submitted_from_inside_a_job() -> None:
+    worker = InlineWorker()
+    order: list[str] = []
+
+    def outer() -> None:
+        order.append("outer start")
+        worker.submit(lambda: order.append("inner"))
+        order.append("outer end")
+
+    worker.submit(outer)
+    assert order == ["outer start", "outer end", "inner"]
+    assert not worker.busy