M7.2: share the loop's parts

Shared parts, not a shared scheduler (agreed): nisse-review will have its
own small scheduler; a common one waits until two exist to compare.

- nisse_core.loop.driver: the driver run, moved; the agent names its
  waiting tools per run (nisse-dev's are WAITING_TOOLS), and execution
  goes to any Executor (ToolOutcome moves with it).
- nisse_core.loop.tools: the tool helper and the tools any agent offers
  (notes, memory, memory_done, ask_expert); nisse_core.loop.expert.
- nisse_core.knowledge.handlers: Knowledge, the vault and memory as
  control tools, the index and prompt text, out of LoopAgent.
- nisse_core.config: file reading, references, people, tuning sections of
  the agent's own, LLM numbers, the vault.
- New core tests: a driver run with a non-workspace executor and the
  agent's own waiting set; Knowledge alone; the shared config pieces.

Docs: the Development Plan marks M7.2 done; Architecture Part L and the
nisse-core README name the new parts.

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

@@ -21,12 +21,12 @@ from nisse_core.gitea import (
     ReviewNote,
 )
 from nisse_core.log.canonical import ToolCall
+from nisse_core.loop.driver import Driver
 from nisse_core.oplog import OpLog
 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
 from nisse_dev.loop.items import ANSWER, MERGE, WAITING, loop_of
 from nisse_dev.loop.milestones import OPEN_PR, Milestones
 from nisse_dev.state import StateStore