Keep hidden utility profile out of new chats

Normalize legacy global settings that still select the internal default profile to Agent 0. This keeps fresh chats aligned with the visible profile catalog while preserving existing chat selections.

helpers/settings.py

@@ -434,6 +434,9 @@ def normalize_settings(settings: Settings) -> Settings:
             except (ValueError, TypeError):
                 copy[key] = value  # make default instead
 
+    if copy["agent_profile"] == "default":
+        copy["agent_profile"] = "agent0"
+
     # mcp server token is set automatically
     copy["mcp_server_token"] = create_auth_token()
     copy["max_consecutive_unusable_responses"] = max(

helpers/settings.py.dox.md

@@ -71,6 +71,8 @@
   A currently configured unavailable profile remains visible with an explicit
   unavailable label so settings can round-trip it truthfully, except that the
   exact `default` utility profile is never offered as a selectable option.
+- Legacy settings that still name the hidden `default` utility profile normalize
+  to `agent0`, so newly created chats always start with a selectable profile.
 - Keep request/response, tool, or helper semantics documented here at the same time as source changes.
 
 ## Work Guidance

tests/test_subagent_profiles.py

@@ -5,7 +5,7 @@ from types import SimpleNamespace
 import pytest
 
 from agent import Agent, AgentConfig, AgentContext
-from helpers import persist_chat, projects
+from helpers import persist_chat, projects, settings
 from helpers.errors import RepairableException
 
 
@@ -34,6 +34,13 @@ class _FakeParentAgent:
         return ""
 
 
+def test_hidden_default_profile_normalizes_to_agent0() -> None:
+    configured = settings.get_default_settings()
+    configured["agent_profile"] = "default"
+
+    assert settings.normalize_settings(configured)["agent_profile"] == "agent0"
+
+
 class _FakeSubAgent:
     DATA_NAME_SUPERIOR = "_superior"
     DATA_NAME_SUBORDINATE = "_subordinate"