telegram: add error handlers to stop silent polling death

The bot would silently stop delivering messages after the first error:
grammy's default handler calls bot.stop() on any middleware throw, and
void bot.start() / void mcp.notification() swallow rejections with no log.

- bot.catch(): log and keep polling on handler errors
- bot.start().catch(): log when polling dies (bad token, 409, network)
- mcp.notification().catch(): log when inbound delivery to Claude fails
- process-level unhandledRejection/uncaughtException as a safety net

Fixes #756 #759 #761 #777 #809, partial #788

external_plugins/telegram/server.ts

@@ -51,6 +51,15 @@ if (!TOKEN) {
 }
 const INBOX_DIR = join(STATE_DIR, 'inbox')
 
+// Last-resort safety net — without these the process dies silently on any
+// unhandled promise rejection. With them it logs and keeps serving tools.
+process.on('unhandledRejection', err => {
+  process.stderr.write(`telegram channel: unhandled rejection: ${err}\n`)
+})
+process.on('uncaughtException', err => {
+  process.stderr.write(`telegram channel: uncaught exception: ${err}\n`)
+})
+
 const bot = new Bot(TOKEN)
 let botUsername = ''
 
@@ -372,11 +381,6 @@ mcp.setRequestHandler(ListToolsRequestSchema, async () => ({
             items: { type: 'string' },
             description: 'Absolute file paths to attach. Images send as photos (inline preview); other types as documents. Max 50MB each.',
           },
-          format: {
-            type: 'string',
-            enum: ['text', 'markdownv2'],
-            description: "Rendering mode. 'markdownv2' enables Telegram formatting (bold, italic, code, links). Caller must escape special chars per MarkdownV2 rules. Default: 'text' (plain, no escaping needed).",
-          },
         },
         required: ['chat_id', 'text'],
       },
@@ -403,11 +407,6 @@ mcp.setRequestHandler(ListToolsRequestSchema, async () => ({
           chat_id: { type: 'string' },
           message_id: { type: 'string' },
           text: { type: 'string' },
-          format: {
-            type: 'string',
-            enum: ['text', 'markdownv2'],
-            description: "Rendering mode. 'markdownv2' enables Telegram formatting (bold, italic, code, links). Caller must escape special chars per MarkdownV2 rules. Default: 'text' (plain, no escaping needed).",
-          },
         },
         required: ['chat_id', 'message_id', 'text'],
       },
@@ -424,8 +423,6 @@ mcp.setRequestHandler(CallToolRequestSchema, async req => {
         const text = args.text as string
         const reply_to = args.reply_to != null ? Number(args.reply_to) : undefined
         const files = (args.files as string[] | undefined) ?? []
-        const format = (args.format as string | undefined) ?? 'text'
-        const parseMode = format === 'markdownv2' ? 'MarkdownV2' as const : undefined
 
         assertAllowedChat(chat_id)
 
@@ -452,7 +449,6 @@ mcp.setRequestHandler(CallToolRequestSchema, async req => {
               (replyMode === 'all' || i === 0)
             const sent = await bot.api.sendMessage(chat_id, chunks[i], {
               ...(shouldReplyTo ? { reply_parameters: { message_id: reply_to } } : {}),
-              ...(parseMode ? { parse_mode: parseMode } : {}),
             })
             sentIds.push(sent.message_id)
           }
@@ -495,13 +491,10 @@ mcp.setRequestHandler(CallToolRequestSchema, async req => {
       }
       case 'edit_message': {
         assertAllowedChat(args.chat_id as string)
-        const editFormat = (args.format as string | undefined) ?? 'text'
-        const editParseMode = editFormat === 'markdownv2' ? 'MarkdownV2' as const : undefined
         const edited = await bot.api.editMessageText(
           args.chat_id as string,
           Number(args.message_id),
           args.text as string,
-          ...(editParseMode ? [{ parse_mode: editParseMode }] : []),
         )
         const id = typeof edited === 'object' ? edited.message_id : args.message_id
         return { content: [{ type: 'text', text: `edited (id: ${id})` }] }
@@ -593,7 +586,7 @@ async function handleInbound(
 
   // image_path goes in meta only — an in-content "[image attached — read: PATH]"
   // annotation is forgeable by any allowlisted sender typing that string.
-  void mcp.notification({
+  mcp.notification({
     method: 'notifications/claude/channel',
     params: {
       content: text,
@@ -606,12 +599,25 @@ async function handleInbound(
         ...(imagePath ? { image_path: imagePath } : {}),
       },
     },
+  }).catch(err => {
+    process.stderr.write(`telegram channel: failed to deliver inbound to Claude: ${err}\n`)
   })
 }
 
-void bot.start({
+// Without this, any throw in a message handler stops polling permanently
+// (grammy's default error handler calls bot.stop() and rethrows).
+bot.catch(err => {
+  process.stderr.write(`telegram channel: handler error (polling continues): ${err.error}\n`)
+})
+
+bot.start({
   onStart: info => {
     botUsername = info.username
     process.stderr.write(`telegram channel: polling as @${info.username}\n`)
   },
+}).catch(err => {
+  // bot.start() only rejects if polling can't begin or dies unrecoverably —
+  // bad token, 409 conflict, network gone. Log it so the user isn't left
+  // wondering why messages stopped arriving.
+  process.stderr.write(`telegram channel: polling stopped: ${err}\n`)
 })