Addresses reviewer concerns regarding silent message loss by narrowing the
error swallowing logic in EditMessage:
- Excludes context.DeadlineExceeded and context.Canceled from being swallowed,
ensuring local timeouts before transmission still trigger a fallback send.
- Adds an explicit check for the 'message is not modified' error to safely
identify edits that have already landed on Telegram's servers.
- Narrowly targets confirmed post-connect dropouts (e.g., connection reset)
instead of broad network-ish string matching.
- Fixes the missing isPostConnectError definition and required errors import.
b90a6d12ea