M2.8: switch over to the new loop

nisse-dev now runs only the conversational loop. The gated state machine
it was built alongside is gone:

- Removed control.py, planner.py, executor.py, approvals.py, gates.py
  (command_form moves to loop/reader.py), publish.py and poller.py, the
  old assembly in agent.py (its shared helpers move to loop/build.py),
  the store's state-machine view (get_state, transition), their tests,
  the old end-to-end and live planning/milestone/gate tests, and
  specs/orchestrator.qnt with its scenarios.
- Roles are driver, helper, expert and classifier; driver is required.
  loop:, roles.planner, roles.executor and tuning.executor are refused
  with what to use instead; tuning.driver takes the turn cap and failure
  limit.
- The benchmark and the capability matrix measure the driver: the
  loop's own system prompt and tools, the task's plan as the agreed
  restatement. Task plans end with finish_milestone, so earlier runs
  show as (old); stored runs' executor tuning reads as the driver's.
- A delegation on the loop records what its helper's alias resolved to
  (L9), as the old path's did.
- The dump shows a work item's revision and what it waits for.
- Behaviour the old tests covered and the loop shares stays covered:
  driver runs that fail on a model call, stop mid-turn, reset the
  failure count; go-aheads ignoring case and punctuation; a request too
  big to fit is never sent; the assembly tests, now on build_loop_agent.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPQ14L3LikyefCMFBqEbKE

nisse-dev/src/nisse_dev/main.py

@@ -12,9 +12,9 @@ import sys
 from pathlib import Path
 from types import FrameType
 
-from nisse_dev.agent import build_agent
 from nisse_dev.config import AgentConfig, ConfigError
 from nisse_dev.envfile import load_env_file
+from nisse_dev.loop.build import build_loop_agent
 
 
 def main() -> int:
@@ -27,12 +27,7 @@ def main() -> int:
         print(f"nisse-dev: {exc}", file=sys.stderr)
         return 2
 
-    if config.loop == "new":
-        from nisse_dev.loop.build import build_loop_agent
-
-        agent = build_loop_agent(config)
-    else:
-        agent = build_agent(config)
+    agent = build_loop_agent(config)
 
     def shutdown(_signum: int, _frame: FrameType | None) -> None:
         print("nisse-dev: stopping", file=sys.stderr)
@@ -42,7 +37,8 @@ def main() -> int:
     signal.signal(signal.SIGTERM, shutdown)
 
     agent.start()
-    print(f"nisse-dev: ready as {agent.account} on {config.project}", file=sys.stderr)
+    names = ", ".join(p.name for p in config.projects)
+    print(f"nisse-dev: ready as {agent.account} on {names}", file=sys.stderr)
     agent.wait()
     return 0