feat(tabs): COD-359 add owner-scoped tab layouts

src/web/session-order-sse.ts

@@ -0,0 +1,15 @@
+/** @fileoverview Trusted per-recipient payload selection for legacy session-order invalidations. */
+import type { SessionOrderProjectionChange } from '../tab-layout-service.js';
+import type { AuthUser } from '../types.js';
+
+export function sessionOrderPayloadFor(
+  identity: AuthUser | undefined,
+  change: SessionOrderProjectionChange
+): { order: string[] } | undefined {
+  if (!identity || identity.role === 'admin') {
+    return change.globalChanged ? { order: [...change.globalOrder] } : undefined;
+  }
+  if (!Object.hasOwn(change.changedOwnerOrders, identity.username)) return undefined;
+  const order = change.changedOwnerOrders[identity.username];
+  return Array.isArray(order) ? { order: [...order] } : undefined;
+}