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-core/tests/test_dump.py

@@ -1,10 +1,16 @@
 import io
 from pathlib import Path
 
-from nisse_core.canonical import Fact, PlanSubmitted, ToolCall, ToolResult, UserMessage
-from nisse_core.dump import main, render
+from nisse_core.log.canonical import (
+    Fact,
+    PlanSubmitted,
+    ToolCall,
+    ToolResult,
+    UserMessage,
+)
 from nisse_core.oplog import OpLog
-from nisse_core.state import StateStore
+from nisse_core.state.dump import main, render
+from nisse_core.state.store import StateStore
 
 
 def store_with_a_run(path: Path) -> None: