fix: task embed 편집, metadata 중복 제거, closed- 채널 복원

bot.py

@@ -186,6 +186,8 @@ class GravityBot(commands.Bot):
         self._channel_locks: dict[str, asyncio.Lock] = {}
         # Bridge protocol for bidirectional communication
         self.bridge = BridgeProtocol()
+        # Cache: conversation_id -> last metadata summary (skip unchanged)
+        self._last_meta_summary: dict[str, str] = {}
         # Category for session channels
         self.session_category: discord.CategoryChannel | None = None
         # Guild reference
@@ -270,6 +272,16 @@ class GravityBot(commands.Bot):
                     if ch.topic and conversation_id in ch.topic:
                         self.session_channels[conversation_id] = ch
                         self.session_names[conversation_id] = project_name
+                        # Rename back from closed- if needed
+                        expected_name = f"{Config.CHANNEL_PREFIX}-{project_name}"
+                        if ch.name != expected_name.lower():
+                            try:
+                                await ch.edit(name=expected_name)
+                                logger.info(f"Renamed channel {ch.name} -> {expected_name}")
+                            except discord.errors.Forbidden:
+                                pass
+                        # Recover last task embed message ID
+                        await self._recover_task_message(ch, conversation_id)
                         logger.info(f"Reconnected to existing channel #{ch.name}")
                         return ch
 
@@ -301,6 +313,24 @@ class GravityBot(commands.Bot):
                 logger.error(f"No permission to create channel: {channel_name}")
                 return None
 
+    async def _recover_task_message(
+        self, channel: discord.TextChannel, conversation_id: str
+    ):
+        """Find the last task embed in channel history to reuse for editing."""
+        if conversation_id in self.session_status_messages:
+            return  # Already have it
+
+        try:
+            async for msg in channel.history(limit=20):
+                if msg.author == self.user and msg.embeds:
+                    embed = msg.embeds[0]
+                    if embed.title and "Task 진행 현황" in embed.title:
+                        self.session_status_messages[conversation_id] = msg.id
+                        logger.info(f"Recovered task embed msg {msg.id} for {conversation_id[:8]}")
+                        return
+        except (discord.Forbidden, discord.HTTPException):
+            pass
+
     async def _process_events(self):
         """Main event processing loop."""
         await self.wait_until_ready()
@@ -407,11 +437,16 @@ class GravityBot(commands.Bot):
 
         summary = meta.get("summary", "")
         artifact_type = meta.get("artifactType", "")
-        updated_at = meta.get("updatedAt", "")
 
         if not summary:
             return
 
+        # Dedup: skip if summary unchanged since last notification
+        cache_key = f"{event.conversation_id}:{event.file_name}"
+        if self._last_meta_summary.get(cache_key) == summary:
+            return
+        self._last_meta_summary[cache_key] = summary
+
         # Map artifact types to emoji
         type_emoji = {
             "ARTIFACT_TYPE_TASK": "📋",