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/src/nisse_dev/config.py

@@ -36,8 +36,8 @@ REQUIRED_KEYS = (
     "llm.token",
     "roles.executor",
     "roles.planner",
-    "roles.delegate",
-    "roles.consultant",
+    "roles.helper",
+    "roles.expert",
     "matrix.homeserver",
     "matrix.user_id",
     "matrix.token",
@@ -312,8 +312,8 @@ class AgentConfig:
             roles=RoleMap(
                 executor=str(values["roles.executor"]),
                 planner=str(values["roles.planner"]),
-                delegate=str(values["roles.delegate"]),
-                consultant=str(values["roles.consultant"]),
+                helper=str(values["roles.helper"]),
+                expert=str(values["roles.expert"]),
             ),
             matrix=MatrixConfig(
                 homeserver=str(values["matrix.homeserver"]).rstrip("/"),
@@ -371,5 +371,5 @@ class AgentConfig:
             "repo": self.gitea_repo,
             "planner": self.roles.planner,
             "executor": self.roles.executor,
-            "delegate": self.roles.delegate,
+            "helper": self.roles.helper,
         }