Rename the delegate and consultant roles to helper and expert

Architecture L9's role names, for the two roles with a direct
counterpart: the delegation role is now 'helper' and the ask_expert role
'expert', in RoleMap, configuration (roles.helper, roles.expert),
recorded events and tests. 'planner' and 'executor' stay distinct for
now; they become 'driver' when the new loop merges them (Development
Plan M2.3).

Configurations must rename their keys: nisse-dev.example.yaml and
tests/integration/nisse-test.yaml are updated here.

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

nisse-dev/tests/test_config.py

@@ -16,8 +16,8 @@ COMPLETE: dict[str, Any] = {
     "roles": {
         "executor": "claude-haiku-4-5",
         "planner": "claude-opus-5",
-        "delegate": "claude-opus-5",
-        "consultant": "claude-haiku-4-5",
+        "helper": "claude-opus-5",
+        "expert": "claude-haiku-4-5",
     },
     "matrix": {
         "homeserver": "https://matrix.test/",
@@ -210,8 +210,8 @@ llm: {base_url: "https://litellm.test", token: "${TEST_LLM_TOKEN}"}
 roles:
   executor: local-fast
   planner: claude-opus-5
-  delegate: claude-opus-5
-  consultant: claude-haiku-4-5
+  helper: claude-opus-5
+  expert: claude-haiku-4-5
 matrix:
   homeserver: https://matrix.test
   user_id: "@nisse-dev-testing:test"