Adopt structured agent thread rows (author_kind/event/payload)

Types the new TaskThreadMessage fields from PostHog/posthog#70371 (stacked on #70320) and keys agent rendering on author_kind, keeping the authorless fallback for older backends. payload.run_id on turn_complete rows is the dedupe key for live session-derived agent turn views.

Generated-By: PostHog Code
Task-Id: ea09a661-1f6d-4bd8-a046-24be60909d28

Author: k11kirky

packages/shared/src/domain-types.ts

@@ -86,6 +86,12 @@ export interface TaskChannel {
 export interface TaskThreadMessage {
   id: string;
   task: string;
+  /** Who authored the row; agent rows are server-emitted announcements. Absent on older backends. */
+  author_kind?: "human" | "system" | "agent";
+  /** Stable event key for non-human rows (e.g. "canvas_created", "turn_complete"). */
+  event?: string;
+  /** Structured event payload; turn_complete carries `{ run_id }` so a client rendering a run's live agent turns can dedupe the durable row. */
+  payload?: Record<string, unknown>;
   content: string;
   created_at: string;
   author?: UserBasic | null;

packages/ui/src/features/canvas/components/ThreadPanel.tsx

@@ -65,9 +65,11 @@ function ThreadMessageRow({
 }) {
   const forwarded = !!message.forwarded_to_agent_at;
   const showMenu = (isTaskAuthor && !forwarded) || isOwnMessage;
-  // Authorless messages are posted by the backend on the agent's behalf
-  // (canvas created, turn complete).
-  const isAgent = !message.author;
+  // Agent rows are server-emitted announcements (canvas created, turn complete).
+  // author_kind is authoritative; authorless is the pre-author_kind fallback.
+  const isAgent =
+    message.author_kind === "agent" ||
+    (!message.author_kind && !message.author);
 
   return (
     <div className="group flex gap-2 rounded-md px-2 py-1.5 hover:bg-fill-secondary">