fix(telegram): drop ppid watchdog check; redirect bun install stdout to stderr

Two v0.0.5/0.0.6 regressions causing the plugin to fail at startup:

1. The orphan watchdog's process.ppid !== bootPpid check false-fires when the
   bun-run/shell wrapper exits or execs during normal startup and we get
   reparented to init — plugin self-terminates ~5s after launch. Stdin-close
   alone is the correct signal: the kernel closes the MCP pipe on any CLI
   death regardless of intermediate wrappers, so the ppid check was both
   unnecessary and harmful. (#1467; also the actual cause of #1459 item 3
   and likely #1425.)

2. 'bun install --no-summary' in the start script writes to stdout, which is
   the MCP JSON-RPC transport. The harness sees non-JSON bytes during the
   handshake and drops the connection ('Failed to connect'). Redirect install
   output to stderr. (#1470; also explains #1425 on Windows.)

external_plugins/telegram/package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "bin": "./server.ts",
   "scripts": {
-    "start": "bun install --no-summary && bun server.ts"
+    "start": "bun install --no-summary 1>&2 && bun server.ts"
   },
   "dependencies": {
     "@modelcontextprotocol/sdk": "^1.0.0",