feat(telegram): add silent message option (#2382)

* feat(telegram): add silent message option (disable_notification)

Add support for sending Telegram messages silently without notification
sound via the `silent` parameter on the message tool.

Changes:
- Add `silent` boolean to message tool schema
- Extract and pass `silent` through telegram plugin
- Add `disable_notification: true` to Telegram API calls
- Add `--silent` flag to CLI `message send` command
- Add unit test for silent flag

Closes #2249

AI-assisted (Claude) - fully tested with unit tests + manual Telegram testing

* feat(telegram): add silent send option (#2382) (thanks @Suksham-sharma)

---------

Co-authored-by: Pocket Clawd <pocket@Pockets-Mac-mini.local>

src/agents/tools/message-tool.ts

@@ -59,6 +59,7 @@ function buildSendSchema(options: { includeButtons: boolean; includeCards: boole
     replyTo: Type.Optional(Type.String()),
     threadId: Type.Optional(Type.String()),
     asVoice: Type.Optional(Type.Boolean()),
+    silent: Type.Optional(Type.Boolean()),
     bestEffort: Type.Optional(Type.Boolean()),
     gifPlayback: Type.Optional(Type.Boolean()),
     buttons: Type.Optional(