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

scripts/e2e.sh

@@ -36,7 +36,7 @@ else
     export NISSE_E2E_BUILD_HOST=${NISSE_E2E_BUILD_HOST:-nisse-dev.garrett-hall.com}
     export NISSE_E2E_BUILD_KEY=${NISSE_E2E_BUILD_KEY:-/root/nisse-e2e/ssh/id_ed25519}
 fi
-# Each run's state store is kept here, for nisse_core.dump after a failure.
+# Each run's state store is kept here, for nisse_core.state.dump after a failure.
 export NISSE_E2E_RUNS=${NISSE_E2E_RUNS:-/root/nisse-e2e/test-runs}
 
 # What the run spent on the test key, read from LiteLLM (spend only). The