Show live task progress while agents work (#3227)

* feat(agents): surface live task progress

Keep current task state above the composer and turn task snapshots into semantic timeline activity. Normalize provider task protocols while preserving genuine plan flows.

* fix(agents): admit tasks through stream sequencing

* test(agents): expect normalized task status

packages/app/src/timeline/session-stream-reducers.test.ts

@@ -3557,6 +3557,59 @@ describe("processAgentStreamEvent", () => {
     expect(result.sideEffects).toEqual([]);
   });
 
+  it("publishes task snapshots only from accepted timeline events", () => {
+    const tasks = [
+      { id: "inspect", text: "Inspect", status: "in_progress" as const, completed: false },
+    ];
+    const event: AgentStreamEventPayload = {
+      type: "timeline",
+      provider: "codex",
+      item: {
+        type: "todo",
+        items: tasks,
+      },
+    };
+    const currentCursor: TimelineCursor = {
+      epoch: "epoch-1",
+      startSeq: 1,
+      endSeq: 4,
+    };
+
+    const accepted = processAgentStreamEvent({
+      ...baseStreamInput,
+      event,
+      seq: 5,
+      epoch: "epoch-1",
+      currentCursor,
+    });
+    const stale = processAgentStreamEvent({
+      ...baseStreamInput,
+      event,
+      seq: 4,
+      epoch: "epoch-1",
+      currentCursor,
+    });
+    const wrongEpoch = processAgentStreamEvent({
+      ...baseStreamInput,
+      event,
+      seq: 5,
+      epoch: "epoch-2",
+      currentCursor,
+    });
+    const gapped = processAgentStreamEvent({
+      ...baseStreamInput,
+      event,
+      seq: 8,
+      epoch: "epoch-1",
+      currentCursor,
+    });
+
+    expect(accepted.taskSnapshot).toEqual(tasks);
+    expect(stale.taskSnapshot).toBeUndefined();
+    expect(wrongEpoch.taskSnapshot).toBeUndefined();
+    expect(gapped.taskSnapshot).toBeUndefined();
+  });
+
   it("detects gap and emits catch-up side effect", () => {
     const existingCursor: TimelineCursor = {
       epoch: "epoch-1",

packages/app/src/timeline/session-stream-reducers.ts

@@ -1,6 +1,6 @@
 import type { AgentStreamEventPayload } from "@getpaseo/protocol/messages";
 import { selectAgentTimelineState, useSessionStore } from "@/stores/session-store";
-import type { AssistantMessageItem, StreamItem } from "@/types/stream";
+import type { AssistantMessageItem, StreamItem, TodoEntry } from "@/types/stream";
 import type { TurnLivenessTransition } from "@/timeline/turn-liveness";
 import {
   applyStreamEvent,
@@ -1436,6 +1436,7 @@ export interface ProcessAgentStreamEventOutput {
   cursor: TimelineCursor | null;
   cursorChanged: boolean;
   acknowledgedClientMessageIds: string[];
+  taskSnapshot?: TodoEntry[];
   sideEffects: AgentStreamReducerSideEffect[];
 }
 
@@ -1642,6 +1643,9 @@ export function processAgentStreamEvent(
     cursor: sequencing.nextTimelineCursor,
     cursorChanged: sequencing.cursorChanged,
     acknowledgedClientMessageIds: streamResult.acknowledgedClientMessageIds ?? [],
+    ...(sequencing.shouldApplyStreamEvent && event.type === "timeline" && event.item.type === "todo"
+      ? { taskSnapshot: event.item.items }
+      : {}),
     sideEffects: sequencing.sideEffects,
   };
 }
@@ -1667,6 +1671,7 @@ export function processAgentStreamEvents(
   let changedTail = false;
   let changedHead = false;
   let cursorChanged = false;
+  let taskSnapshot: TodoEntry[] | undefined;
   const acknowledgedClientMessageIds = new Set<string>();
   const sideEffects: AgentStreamReducerSideEffect[] = [];
 
@@ -1690,6 +1695,9 @@ export function processAgentStreamEvents(
     for (const clientMessageId of result.acknowledgedClientMessageIds) {
       acknowledgedClientMessageIds.add(clientMessageId);
     }
+    if (result.taskSnapshot !== undefined) {
+      taskSnapshot = result.taskSnapshot;
+    }
 
     if (result.cursorChanged) {
       cursor = result.cursor ?? undefined;
@@ -1705,6 +1713,7 @@ export function processAgentStreamEvents(
     cursor: cursor ?? null,
     cursorChanged,
     acknowledgedClientMessageIds: [...acknowledgedClientMessageIds],
+    ...(taskSnapshot !== undefined ? { taskSnapshot } : {}),
     sideEffects,
   };
 }
@@ -1788,6 +1797,7 @@ interface StreamStatePatch {
   tail?: StreamItem[];
   head?: StreamItem[];
   acknowledgedClientMessageIds?: readonly string[];
+  taskSnapshot?: TodoEntry[];
 }
 
 export function deriveAgentStreamTurnLiveness(
@@ -1850,7 +1860,8 @@ export function createSessionAgentStreamReducerQueue(
       if (
         result.changedTail ||
         result.changedHead ||
-        result.acknowledgedClientMessageIds.length > 0
+        result.acknowledgedClientMessageIds.length > 0 ||
+        result.taskSnapshot !== undefined
       ) {
         setAgentStreamState(serverId, agentId, {
           ...(result.changedTail ? { tail: result.tail } : {}),
@@ -1858,6 +1869,7 @@ export function createSessionAgentStreamReducerQueue(
           ...(result.acknowledgedClientMessageIds.length > 0
             ? { acknowledgedClientMessageIds: result.acknowledgedClientMessageIds }
             : {}),
+          ...(result.taskSnapshot !== undefined ? { taskSnapshot: result.taskSnapshot } : {}),
         });
       }
       if (result.cursorChanged && result.cursor) {