nisse-core: group modules into packages by architecture section

A pure move; behaviour unchanged.

- models (L9, L7): llm, catalog, probe, render, render_anthropic, context
- log (L7, L6): canonical, views
- state (L8): store (was state), reconcile, worker, cancel, dump
- knowledge (L10, L6.4): vault, memory
- conversation (L5): transport, matrix
- execution (L13): ssh (was execution), testing
- authority (P3, P4, L4): actions
- gitea, oplog, envfile stay at the top until each gains a second module.

Every import, monkeypatch target, script and doc reference rewritten.

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

nisse-dev/tests/test_loop_milestones.py

@@ -10,9 +10,8 @@ from typing import Any
 import pytest
 from model_contract import assert_renderable
 
-from nisse_core.cancel import Cancel
-from nisse_core.canonical import ToolCall
-from nisse_core.execution import SSHHost
+from nisse_core.conversation.transport import InMemoryTransport
+from nisse_core.execution.ssh import SSHHost
 from nisse_core.gitea import (
     Approval,
     Comment,
@@ -21,9 +20,10 @@ from nisse_core.gitea import (
     PullRequest,
     ReviewNote,
 )
+from nisse_core.log.canonical import ToolCall
 from nisse_core.oplog import OpLog
-from nisse_core.transport import InMemoryTransport
-from nisse_core.worker import InlineWorker
+from nisse_core.state.cancel import Cancel
+from nisse_core.state.worker import InlineWorker
 from nisse_dev.git import GitRepo
 from nisse_dev.loop.agent import LoopAgent
 from nisse_dev.loop.driver import Driver