feat: web multi session interface

channel/web/web_channel.py

@@ -91,39 +91,9 @@ def _get_upload_dir() -> str:
 
 
 def _generate_session_title(user_message: str, assistant_reply: str = "") -> str:
-    """
-    Generate a short session title by calling the current bot's reply_text.
-    """
-    import re
-    fallback = user_message[:50].split("\n")[0].strip() or "New Chat"
-    try:
-        from bridge.bridge import Bridge
-        from models.session_manager import Session
-        bot = Bridge().get_bot("chat")
-
-        prompt_parts = [f"User: {user_message[:300]}"]
-        if assistant_reply:
-            prompt_parts.append(f"Assistant: {assistant_reply[:300]}")
-
-        session = Session("__title_gen__", system_prompt="")
-        session.messages = [
-            {"role": "user", "content": (
-                "Generate a very short title (max 15 characters for Chinese, max 6 words for English) "
-                "summarizing this conversation. Return ONLY the title text, nothing else.\n\n"
-                + "\n".join(prompt_parts)
-            )}
-        ]
-
-        result = bot.reply_text(session)
-        raw = (result.get("content") or "").strip()
-        # Strip <think>...</think> reasoning blocks
-        title = re.sub(r'<think>.*?</think>', '', raw, flags=re.DOTALL).strip().strip('"\'')
-        logger.info(f"[WebChannel] Title generation result: '{title}' (len={len(title)})")
-        if title and len(title) <= 50:
-            return title
-    except Exception as e:
-        logger.warning(f"[WebChannel] Title generation failed: {e}")
-    return fallback
+    """Delegate to the shared SessionService implementation."""
+    from agent.chat.session_service import generate_session_title
+    return generate_session_title(user_message, assistant_reply)
 
 
 class WebMessage(ChatMessage):