The Signal and iMessage channel plugins inferred approval prompts by
regex-sniffing rendered message text (header matching like 'Exec approval
required', /approve command parsing), violating the transport-only channel
doctrine: approval actions must stay typed until channel encoding.
The typed envelope already existed (channelData.execApproval with
approvalId/approvalKind/allowedDecisions) and every payload-level delivery
path consumed it; the regex paths were redundant re-derivation at the raw
send seam plus restart recovery for in-memory iMessage poll state.
- Signal: delete send-level prompt sniffing entirely; all approval sends
already flow through typed structured-payload or native-handler paths.
- iMessage: sendMessageIMessage takes a typed approvalPrompt binding
(id/kind/decisions) from the native approval handler instead of an
approvalKind flag plus text re-parsing.
- iMessage poller: persist pending poll targets in the plugin keyed store
so restart recovery no longer regex-scans chat history; typed recent-chat
discovery for handle-only DM targets stays. Split poll-target ownership
into approval-reaction-poll-targets.ts (max-lines).
- Plugin SDK: remove extractApprovalReactionPromptBinding — beta-only
surface, never in a stable release, so no deprecation window applies;
AGENTS.md now records that rule.
Accepted tradeoff: approval prompts delivered by a pre-upgrade process are
not rediscovered from chat text after restart (<=24h transient state;
persisted reaction bindings and event-driven tapbacks still work).
Peter Steinberger
a0f4d5462a