Add LLM request queue, streaming chat, and rename ollama_client to llm_client

- Serialize all LLM requests through an asyncio semaphore to prevent
  overloading athena with concurrent requests
- Switch chat() to streaming so the typing indicator only appears once
  the model starts generating (not during thinking/loading)
- Increase LLM timeout from 5 to 10 minutes for slow first loads
- Rename ollama_client.py to llm_client.py and self.ollama to self.llm
  since the bot uses a generic OpenAI-compatible API
- Update embed labels from "Ollama" to "LLM"

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

cogs/sentiment.py

@@ -82,7 +82,7 @@ class SentimentCog(commands.Cog):
         # Analyze the message
         context = self._get_context(message)
         user_notes = self.bot.drama_tracker.get_user_notes(message.author.id)
-        result = await self.bot.ollama.analyze_message(
+        result = await self.bot.llm.analyze_message(
             message.content, context, user_notes=user_notes
         )