feat(telegram): add location/geo support

Forward static location pins as [location: lat, lon] content so the
agent can respond to geo messages and pass coordinates to MCP tools.

Closes HKUDS/nanobot#2909

nanobot/channels/telegram.py

@@ -316,10 +316,10 @@ class TelegramChannel(BaseChannel):
         )
         self._app.add_handler(MessageHandler(filters.Regex(r"^/help(?:@\w+)?$"), self._on_help))
 
-        # Add message handler for text, photos, voice, documents
+        # Add message handler for text, photos, voice, documents, and locations
         self._app.add_handler(
             MessageHandler(
-                (filters.TEXT | filters.PHOTO | filters.VOICE | filters.AUDIO | filters.Document.ALL)
+                (filters.TEXT | filters.PHOTO | filters.VOICE | filters.AUDIO | filters.Document.ALL | filters.LOCATION)
                 & ~filters.COMMAND,
                 self._on_message
             )
@@ -884,6 +884,12 @@ class TelegramChannel(BaseChannel):
         if message.caption:
             content_parts.append(message.caption)
 
+        # Location content
+        if message.location:
+            lat = message.location.latitude
+            lon = message.location.longitude
+            content_parts.append(f"[location: {lat}, {lon}]")
+
         # Download current message media
         current_media_paths, current_media_parts = await self._download_message_media(
             message, add_failure_content=True