discord/telegram: guide assistant to send new reply on completion

Message edits don't trigger push notifications on the user's device.
Update system instructions and edit_message tool description to steer
the assistant toward edit-for-progress + new-reply-on-completion.

Fixes #786

external_plugins/telegram/server.ts

@@ -343,7 +343,7 @@ const mcp = new Server(
       '',
       'Messages from Telegram arrive as <channel source="telegram" chat_id="..." message_id="..." user="..." ts="...">. If the tag has an image_path attribute, Read that file — it is a photo the sender attached. Reply with the reply tool — pass chat_id back. Use reply_to (set to a message_id) only when replying to an earlier message; the latest message doesn\'t need a quote-reply, omit reply_to for normal responses.',
       '',
-      'reply accepts file paths (files: ["/abs/path.png"]) for attachments. Use react to add emoji reactions, and edit_message to update a message you previously sent (e.g. progress → result).',
+      'reply accepts file paths (files: ["/abs/path.png"]) for attachments. Use react to add emoji reactions, and edit_message for interim progress updates. Edits don\'t trigger push notifications — when a long task completes, send a new reply so the user\'s device pings.',
       '',
       "Telegram's Bot API exposes no history or search — you only see messages as they arrive. If you need earlier context, ask the user to paste it or summarize.",
       '',
@@ -391,7 +391,7 @@ mcp.setRequestHandler(ListToolsRequestSchema, async () => ({
     },
     {
       name: 'edit_message',
-      description: 'Edit a message the bot previously sent. Useful for progress updates (send "working…" then edit to the result).',
+      description: 'Edit a message the bot previously sent. Useful for interim progress updates. Edits don\'t trigger push notifications — send a new reply when a long task completes so the user\'s device pings.',
       inputSchema: {
         type: 'object',
         properties: {