The Telegram channel capabilities file was missing the `webhook`
block inside `capabilities.channel`, causing the router to fall back
to the default `X-Webhook-Secret` header instead of the Telegram-
specific `X-Telegram-Bot-Api-Secret-Token`.
When a webhook secret is configured (via `telegram_webhook_secret`),
incoming updates are rejected with 401 because Telegram sends the
token in `X-Telegram-Bot-Api-Secret-Token` but the router looks for
`X-Webhook-Secret`.
The existing test in `schema.rs` already expects the correct header
name, confirming this is an oversight in the shipped capabilities
file.
Co-authored-by: SMKRV <[email protected]>
Co-authored-by: firat.sertgoz <[email protected]>
