refactor: consolidate conversation_history to ConversationHistory class

Remove legacy globals.conversation_history (defaultdict of deques) and
route all callers through utils.conversation_history.ConversationHistory:

- globals.py: remove conversation_history + unused collections imports
- llm.py: remove backward-compat dual-write to legacy system
- api.py: /conversation/{user_id} now reads from ConversationHistory
- actions.py: reset_conversation uses clear_channel()
- figurine_notifier.py: use add_message() instead of buggy setdefault()
- bipolar_mode.py: fix clear_history -> clear_channel (was AttributeError
  silently swallowed by bare except), fix bare except -> except Exception

bot/utils/bipolar_mode.py

@@ -1034,8 +1034,8 @@ async def run_argument(channel: discord.TextChannel, client, trigger_context: st
                     
                     # Clean up argument conversation history
                     try:
-                        conversation_history.clear_history(argument_user_id)
-                    except:
+                        conversation_history.clear_channel(argument_user_id)
+                    except Exception:
                         pass  # History cleanup is not critical
                     
                     end_argument(channel_id)

bot/utils/figurine_notifier.py

@@ -5,8 +5,8 @@ from datetime import datetime
 from typing import List, Dict, Any, Tuple
 
 import discord
-import globals
 
+from utils.conversation_history import conversation_history
 from utils.twitter_fetcher import fetch_figurine_tweets_latest
 from utils.image_handling import analyze_image_with_qwen, download_and_encode_image
 from utils.llm import query_llama
@@ -204,15 +204,11 @@ async def send_figurine_dm_to_user(client: discord.Client, user_id: int, tweet:
         # Log the comment message
         dm_logger.log_user_message(user, comment_message, is_bot_message=True)
         
-        # IMPORTANT: Also add to globals.conversation_history for LLM context
+        # Add to conversation history for LLM context (uses centralized ConversationHistory)
         user_id_str = str(user_id)
-        
-        # Add the tweet URL as a "system message" about what Miku just sent (use original URL for context)
         tweet_context = f"[I just sent you this figurine tweet: {tweet_url}]"
-        
-        # Add the figurine comment to conversation history 
-        # Use empty user prompt since this was initiated by Miku
-        globals.conversation_history.setdefault(user_id_str, []).append((tweet_context, miku_comment))
+        conversation_history.add_message(channel_id=user_id_str, author_name="Miku", content=tweet_context, is_bot=True)
+        conversation_history.add_message(channel_id=user_id_str, author_name="Miku", content=miku_comment, is_bot=True)
         
         logger.debug(f"Messages logged to both DM history and conversation context for user {user_id}")
 

bot/utils/llm.py

@@ -475,10 +475,6 @@ Please respond in a way that reflects this emotional tone.{pfp_context}"""
                             is_bot=True
                         )
                     
-                    # Also save to legacy globals for backward compatibility (skip error messages)
-                    if user_prompt and user_prompt.strip() and reply and reply.strip() and reply != "Someone tell Koko-nii there is a problem with my AI.":
-                        globals.conversation_history[user_id].append((user_prompt, reply))
-                    
                     return reply
                 else:
                     error_text = await response.text()