feat: Add persistent user memory system

- Extract and store memorable facts (name, language, preferences) per user
- Inject memories into system prompt for personalized responses
- LLM-based extraction after each response, deduplication against existing
- JSON files on Docker volume (/data/memories), capped at 50 per user
- System prompt updated: respond in users language, use memories
- Commands: !ai memories (view), !ai forget (delete all)

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

docker-compose.yml

@@ -19,6 +19,8 @@ services:
       - WILDFILES_ORG
     volumes:
       - bot-crypto:/data/crypto_store
+      - bot-memories:/data/memories
 
 volumes:
   bot-crypto:
+  bot-memories: