* fix(mobile): clear native-chat composer optimistically at send time
Over relay the send RPC round trip is visible and a lost ack (or a
relay/direct cutover) could strand the sent prompt in the composer
forever: the unconfirmed-send deadline dropped its tracking entry, so a
late transcript echo could never clear the draft.
Clear the draft at send time and restore it only on a definite
rejection. holdUnconfirmedSend now only manages the delivery-unconfirmed
notice; it no longer touches drafts.
* fix(mobile): isolate question answers from composer drafts
8b25cfc0f8