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 = ''
 
@@ -507,62 +516,6 @@ mcp.setRequestHandler(CallToolRequestSchema, async req => {
 
 await mcp.connect(new StdioServerTransport())
 
-// Commands are DM-only. Responding in groups would: (1) leak pairing codes via
-// /status to other group members, (2) confirm bot presence in non-allowlisted
-// groups, (3) spam channels the operator never approved. Silent drop matches
-// the gate's behavior for unrecognized groups.
-
-bot.command('start', async ctx => {
-  if (ctx.chat?.type !== 'private') return
-  const access = loadAccess()
-  if (access.dmPolicy === 'disabled') {
-    await ctx.reply(`This bot isn't accepting new connections.`)
-    return
-  }
-  await ctx.reply(
-    `This bot bridges Telegram to a Claude Code session.\n\n` +
-    `To pair:\n` +
-    `1. DM me anything — you'll get a 6-char code\n` +
-    `2. In Claude Code: /telegram:access pair <code>\n\n` +
-    `After that, DMs here reach that session.`
-  )
-})
-
-bot.command('help', async ctx => {
-  if (ctx.chat?.type !== 'private') return
-  await ctx.reply(
-    `Messages you send here route to a paired Claude Code session. ` +
-    `Text and photos are forwarded; replies and reactions come back.\n\n` +
-    `/start — pairing instructions\n` +
-    `/status — check your pairing state`
-  )
-})
-
-bot.command('status', async ctx => {
-  if (ctx.chat?.type !== 'private') return
-  const from = ctx.from
-  if (!from) return
-  const senderId = String(from.id)
-  const access = loadAccess()
-
-  if (access.allowFrom.includes(senderId)) {
-    const name = from.username ? `@${from.username}` : senderId
-    await ctx.reply(`Paired as ${name}.`)
-    return
-  }
-
-  for (const [code, p] of Object.entries(access.pending)) {
-    if (p.senderId === senderId) {
-      await ctx.reply(
-        `Pending pairing — run in Claude Code:\n\n/telegram:access pair ${code}`
-      )
-      return
-    }
-  }
-
-  await ctx.reply(`Not paired. Send me a message to get a pairing code.`)
-})
-
 bot.on('message:text', async ctx => {
   await handleInbound(ctx, ctx.message.text, undefined)
 })
@@ -633,7 +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,
@@ -646,20 +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`)
-    void bot.api.setMyCommands(
-      [
-        { command: 'start', description: 'Welcome and setup guide' },
-        { command: 'help', description: 'What this bot can do' },
-        { command: 'status', description: 'Check your pairing status' },
-      ],
-      { scope: { type: 'all_private_chats' } },
-    ).catch(() => {})
   },
+}).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`)
 })