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-dev/tests/test_bench.py

@@ -7,6 +7,9 @@ from typing import Any
 
 import pytest
 
+from nisse_core.canonical import AssistantText, ToolCall
+from nisse_core.catalog import ModelFacts
+from nisse_core.execution import SSHHost
 from nisse_dev.bench.results import (
     append,
     load,
@@ -17,10 +20,7 @@ from nisse_dev.bench.results import (
 )
 from nisse_dev.bench.runner import MeteringClient, run_task
 from nisse_dev.bench.tasks import CHECK_DIR, load_tasks
-from nisse_dev.canonical import AssistantText, ToolCall
-from nisse_dev.catalog import ModelFacts
 from nisse_dev.config import DriverTuning, Tuning
-from nisse_dev.execution import SSHHost
 
 # The build VM for every test here: the session's throwaway sshd.
 HOST: SSHHost