476c897439
After sustained Bad Gateway / TimedOut reconnect cycles, the PTB httpx client can enter a state where bot.send_message() returns a valid Message (real message_id) but the message never reaches the recipient. TelegramAdapter.send returns SendResult(success=True) and cron's live-adapter branch marks the run delivered while the message is silently dropped. Add a _send_path_degraded flag. _handle_polling_network_error sets it on reconnect storms; the existing _verify_polling_after_reconnect heartbeat probe clears it once getMe() confirms the Bot client is healthy. While the flag is set, send() short-circuits with SendResult(success=False, retryable=True) so cron falls through to the standalone delivery path (fresh HTTP session). Closes #31165. Co-authored-by: teknium1 <127238744+teknium1@users.noreply.github.com>