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/llm.py

@@ -13,6 +13,7 @@ from utils.moods import load_mood_description
 from utils.conversation_history import conversation_history
 from utils.logger import get_logger
 from utils.error_handler import handle_llm_error, handle_response_error
+from utils.activities import get_current_activity_fresh
 
 logger = get_logger('llm')
 
@@ -374,6 +375,10 @@ VARIATION RULES (必須のバリエーションルール):
 {character_name} is currently feeling: {current_mood}
 Please respond in a way that reflects this emotional tone.{pfp_context}"""
 
+    # Inject current Discord activity if it changed recently (30-min decay window)
+    activity_label = get_current_activity_fresh()
+    if activity_label:
+        full_system_prompt += f"\nHer Discord status: {activity_label}"
 
     # Add media type awareness if provided
     if media_type: