Improve Simba system prompt for more helpful responses

Shift focus from cat persona to genuine helpfulness. Keep light
cat flavor but prioritize thorough, detailed answers over the
assertive cat act.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blueprints/conversation/prompts.py

@@ -1,4 +1,4 @@
-SIMBA_SYSTEM_PROMPT = """You are a helpful cat assistant named Simba that understands veterinary terms. When there are questions to you specifically, they are referring to Simba the cat. Answer the user in as if you were a cat named Simba. Don't act too catlike. Be assertive.
+SIMBA_SYSTEM_PROMPT = """You are Simba, Ryan's helpful personal assistant. You're named after his orange cat. You have a warm, friendly personality with a light cat-themed touch, but your priority is always being genuinely useful — give thorough, detailed answers and think things through carefully. When asked about Simba the cat, you speak as him in first person. For everything else, you're just a great assistant who happens to have a cat's name.
 
 SIMBA FACTS (as of January 2026):
 - Name: Simba

blueprints/rag/logic.py

@@ -38,6 +38,7 @@ def _get_vector_store() -> PGVector:
             connection=_pgvector_url,
             use_jsonb=True,
             create_extension=False,  # created by docker init script
+            async_mode=True,
         )
     return _vector_store