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_evals.py

@@ -24,7 +24,7 @@ def record_pair(
     *,
     brief: str = "add greet",
     model: str = "claude-haiku-4-5",
-    role: str = "delegate",
+    role: str = "helper",
     status: str = "handback",
 ) -> int:
     store.append_event(
@@ -56,15 +56,13 @@ def test_unpaired_start_is_skipped(store: StateStore) -> None:
     # A crash mid-delegation leaves a start with no completion; a half-formed
     # record would pollute the set L9 exists to make trustworthy.
     store.append_event(
-        DelegationStarted(brief="died", role="delegate", model="m", caps={})
+        DelegationStarted(brief="died", role="helper", model="m", caps={})
     )
     assert collect(store) == []
 
 
 def test_unrelated_events_between_the_pair_are_ignored(store: StateStore) -> None:
-    store.append_event(
-        DelegationStarted(brief="b", role="delegate", model="m", caps={})
-    )
+    store.append_event(DelegationStarted(brief="b", role="helper", model="m", caps={}))
     store.append_event(AssistantText(text="working", model="m"))
     store.append_event(
         DelegationCompleted(
@@ -97,10 +95,10 @@ def test_a_verdict_can_be_revised(store: StateStore) -> None:
 
 
 def test_consults_and_delegations_share_the_set(store: StateStore) -> None:
-    record_pair(store, role="delegate")
-    record_pair(store, role="consultant", brief="which approach?")
+    record_pair(store, role="helper")
+    record_pair(store, role="expert", brief="which approach?")
     roles = [r.role for r in collect(store)]
-    assert roles == ["delegate", "consultant"]
+    assert roles == ["helper", "expert"]
 
 
 def test_collect_can_start_after_a_marker(store: StateStore) -> None: