Fix vision pipeline: ffmpeg removal by autoremove, increase vision timeout, reduce frame count, add Discord activity awareness

- bot/Dockerfile: Add ffmpeg to reinstall line after apt-get autoremove
  (autoremove was sweeping up ffmpeg as 'no longer needed' after playwright install)
- bot/utils/image_handling.py: Increase video analysis timeout 120s→300s, 6→3 for Tenor GIFs (GTX 1660 VRAM constraint)
- bot/utils/activities.py: Add _activity_changed_at timestamp tracking,
  get_current_activity_label() and get_current_activity_fresh() with 30-min decay
- bot/utils/cat_client.py: Pass current Discord activity to Cheshire Cat pipeline
- bot/utils/llm.py: Inject current Discord activity into system prompt
- cat-plugins/*: Forward Discord activity through working_memory to personality plugins
- bot/persona/*/preamble.txt: Add Discord status usage guidelines for character prompts
- llama-swap-rocm-config.yaml: Add qwen3.5 model entry for ComfyUI prompt generation
- AGENTS.md: New project documentation file

bot/utils/cat_client.py

@@ -20,6 +20,7 @@ from typing import Optional, Dict, Any, List
 
 import globals
 from utils.logger import get_logger
+from utils.activities import get_current_activity_fresh
 
 logger = get_logger('llm')  # Use existing 'llm' logger component
 
@@ -161,6 +162,10 @@ class CatAdapter:
         # Pass media type so discord_bridge can add MEDIA NOTE to the prompt
         if media_type:
             payload["discord_media_type"] = media_type
+        # Pass current Discord activity if it changed recently (30-min decay window)
+        activity_label = get_current_activity_fresh()
+        if activity_label:
+            payload["discord_activity"] = activity_label
 
         try:
             # Build WebSocket URL from HTTP base URL