Execute Workshop streaming finalization safely

[dcellison]

Summary

• add a production-unused Telegram adapter that executes immutable streaming-finalization edit and send operations
• add a separate worker fixed to conversation replies under the streaming_finalization execution contract
• preserve confirmed operation progress across retry and restart
• classify uncertain lease recovery by edit versus send operation
• document the completed execution foundation and require another explicit cutover review before production registration

Telegram behavior

• edit the exact persisted preview message in the canonical Telegram binding
• use Markdown first and retry once as plain text, matching Kai's established presentation behavior
• accept Telegram's explicit message is not modified response as confirmation that the terminal snapshot already exists
• require successful edit evidence to identify the exact target message
• fail permanently when a preview was deleted or cannot be edited; never replace it with an automatic duplicate send
• execute continuation sends only after the edit has been durably confirmed

Recovery and ambiguity

• confirmed edits and sends are skipped after retry or process restart
• definitive rate limits release only the current operation for bounded retry
• timeout, network ambiguity, invalid success evidence, cancellation, or lease expiry after entering sending becomes terminal uncertainty
• an uncertain edit is reported as delivery_edit_uncertain; an uncertain send retains delivery_send_uncertain
• neither ambiguous operation is automatically retried

Isolation and production safety

• the new worker claims only conversation_reply + streaming_finalization + Telegram text work
• it cannot claim qualification rows or legacy send_fragments work
• the existing worker remains unable to claim streaming-finalization work
• no production handler, startup path, runtime registration, CLI command, or live delivery route uses the new classes
• current Telegram replies, media, voice, commands, schedules, GitHub/generic webhooks, files, and notification-group delivery remain unchanged

Verification

• make check
• make typecheck
• focused finalization adapter/worker tests: 19 passed
• focused Workshop delivery and lifecycle suite: 107 passed
• full suite: 5,383 passed, 1 skipped