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

tests/integration/e2e_support.py

@@ -10,10 +10,10 @@ from collections.abc import Iterator
 from dataclasses import dataclass
 from pathlib import Path
 
+from nisse_core.execution import SSHHost
+from nisse_core.gitea import GiteaClient, GiteaError
+from nisse_core.llm import RoleMap
 from nisse_dev.config import BuildHost
-from nisse_dev.execution import SSHHost
-from nisse_dev.gitea import GiteaClient, GiteaError
-from nisse_dev.llm import RoleMap
 
 # The end-to-end tests run every role on a local model, which costs nothing
 # per call; NISSE_E2E_MODEL overrides it (e.g. claude-haiku-5-5 for a quick,