Expose ollama-roles default_chat for Assistent senior model default.

Write preferred chat tag into Assistent/ollama-roles.json so UI and warmup align with manifest default: true.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/gpu_rent/llm_runtime.py

@@ -182,10 +182,14 @@ def preferred_ollama_model(path: Path) -> str | None:
     return entries[0].name if entries else None
 
 
-def ollama_roles_payload(entries: list[OllamaModelEntry]) -> dict[str, list[str]]:
+def ollama_roles_payload(entries: list[OllamaModelEntry]) -> dict[str, list[str] | str | None]:
+    """Sidecar for Assistent: chat/memory lists + preferred default_chat (manifest default: true)."""
     chat = [e.name for e in entries if e.use == "chat"]
     memory = [e.name for e in entries if e.use == "memory"]
-    return {"chat": chat, "memory": memory}
+    preferred = next((e.name for e in entries if e.use == "chat" and e.default), None)
+    if preferred is None and chat:
+        preferred = chat[0]
+    return {"chat": chat, "memory": memory, "default_chat": preferred}
 
 
 def _ollama_ps_names(payload: object) -> set[str]: