[eric] canvas: an unrelated spawn no longer despawns another agent's revealed subagents; reconcile learns keep-not-create ids (ENG-304)

frontend/src/shared/state/isUserLaunchedSession.ts

@@ -11,6 +11,12 @@ export interface SessionOrigin {
 /** A run that is still working, so its card is worth having on screen. */
 const LIVE_STATUSES: ReadonlySet<string> = new Set(['running', 'waiting_approval']);
 
+/** True for a helper session (sub/browser/invoked agent) whose card can only exist by an explicit
+ * reveal click; reconcile must never delete such a card while its session lives (ENG-304). */
+export function isPlumbingSession(session: SessionOrigin): boolean {
+  return PLUMBING_MODES.has(session.mode);
+}
+
 /** True for a chat the user started themselves, which is the only kind that earns a notification. */
 export function isUserLaunchedSession(session: SessionOrigin): boolean {
   return !session.workflow_run_id && !session.workflow_edit_id && !PLUMBING_MODES.has(session.mode);

frontend/src/shared/state/reconcileKeepsRevealedSubagents.test.ts

@@ -0,0 +1,58 @@
+// ENG-304: spawning an unrelated agent despawned another agent's live subagents. Mechanism:
+// revealSubAgent places cards for plumbing sessions (sub/browser/invoked agents) that
+// deservesCanvasCard filters out of the reconcile id-list forever, so the next id-list change
+// handed reconcileSessions a list without them and its delete loop removed the cards. keepIds is
+// the exemption: delete-immune while the session lives, never create-eligible.
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import path from 'node:path';
+import reducer, { reconcileSessions } from '@/shared/state/dashboardLayoutSlice';
+import { isPlumbingSession, deservesCanvasCard } from '@/shared/state/isUserLaunchedSession';
+
+function seedBoard() {
+  let s = reducer(undefined, { type: '@@init' });
+  const place = (sessionId: string, x: number) => {
+    s = reducer(s, { type: 'dashboardLayout/placeCard', payload: { sessionId, x, y: 100, width: 480, height: 280, expandedSessionIds: [], exact: true } });
+  };
+  place('parent-1', 100);
+  place('sub-1', 700);
+  return { get: () => s, apply: (a: unknown) => { s = reducer(s, a as { type: string }); } };
+}
+
+test('the bug, pinned: without keepIds an unrelated spawn despawns the revealed subagent', () => {
+  const b = seedBoard();
+  b.apply(reconcileSessions({ sessionIds: ['parent-1', 'new-agent'], expandedSessionIds: [] }));
+  assert.equal(b.get().cards['sub-1'], undefined, 'this IS ENG-304; if this starts passing with a card present, the id-list derivation changed');
+  assert.ok(b.get().cards['new-agent'], 'the spawn itself must still land');
+});
+
+test('the fix: keepIds makes the revealed subagent delete-immune', () => {
+  const b = seedBoard();
+  b.apply(reconcileSessions({ sessionIds: ['parent-1', 'new-agent'], expandedSessionIds: [], keepIds: ['sub-1'] }));
+  assert.ok(b.get().cards['sub-1'], 'live subagent card must survive an unrelated spawn');
+  assert.ok(b.get().cards['new-agent']);
+  assert.ok(b.get().cards['parent-1']);
+});
+
+test('keep is not create: a keep id with no card stays cardless', () => {
+  const b = seedBoard();
+  b.apply(reconcileSessions({ sessionIds: ['parent-1'], expandedSessionIds: [], keepIds: ['sub-never-revealed'] }));
+  assert.equal(b.get().cards['sub-never-revealed'], undefined, 'granting cards here would undo the ENG-256 rule');
+});
+
+test('a stopped workflow run still loses its card (keepIds must not cover it)', () => {
+  // The keep set is derived from isPlumbingSession, and a run session is mode "agent": not plumbing.
+  const run = { mode: 'agent', workflow_run_id: 'r1', status: 'completed' };
+  assert.equal(isPlumbingSession(run), false);
+  assert.equal(deservesCanvasCard(run), false);
+  const b = seedBoard();
+  b.apply(reconcileSessions({ sessionIds: ['parent-1'], expandedSessionIds: [], keepIds: [] }));
+  assert.equal(b.get().cards['sub-1'], undefined, 'not in the list, not in keep: deleted, as a stopped run should be');
+});
+
+test('the lifecycle effect actually derives and passes keepIds', () => {
+  const src = fs.readFileSync(path.join(process.cwd(), 'src/app/pages/Dashboard/hooks/lifecycle/useDashboardLifecycle.ts'), 'utf8');
+  assert.ok(src.includes('isPlumbingSession(s)'), 'an exemption nobody computes is a boundary drawn but not enforced');
+  assert.ok(src.includes('expandedSessionIds, keepIds }'), 'keepIds must reach the reducer');
+});