Fix navigation-no-fall e2e on CI: generate UUIDs in Node

The init script called crypto.randomUUID() inside the page, but the CI
origin (http://life-towers:8000) is plain HTTP — not a secure context —
so the call throws, the token/cache never get seeded, and the app boots
empty: waitForSelector('lt-block') times out on every attempt.

Generate the token and seeded tree in Node instead (same pattern as
tasks-overflow.spec.ts) and pass them into addInitScript, which now only
writes localStorage and installs the fall detectors.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/e2e/navigation-no-fall.spec.ts

@@ -1,4 +1,5 @@
 import { test, expect } from '@playwright/test';
+import { randomUUID } from 'node:crypto';
 
 /**
  * Regression: navigating between pages must NOT replay the falling animation.
@@ -17,6 +18,10 @@ import { test, expect } from '@playwright/test';
  *
  * The two pages are seeded into the offline cache with DISJOINT date ranges
  * (destination strictly newer) — the precise condition that triggered the bug.
+ *
+ * All ids (and the token) are generated here in Node — `crypto.randomUUID()`
+ * throws inside the page on the CI origin (http://life-towers:8000), which is
+ * plain HTTP and therefore not a secure context.
  */
 test.describe('navigation does not replay the falling animation', () => {
   test('navigating to a newer-dated page keeps blocks at rest', async ({ page }) => {
@@ -24,18 +29,15 @@ test.describe('navigation does not replay the falling animation', () => {
     const HOUR = 3600;
     const DAY = 86400;
 
-    await page.addInitScript(
-      ({ nowSec, HOUR, DAY }) => {
-        const uuid = () => (crypto as Crypto).randomUUID();
     // baseAgeDays/spacingHrs place each page's done blocks in its own window.
     const tower = (name: string, h: number, baseAgeDays: number) => ({
-          id: uuid(),
+      id: randomUUID(),
       name,
       base_color: { h, s: 0.7, l: 0.55 },
       blocks: [
-            { id: uuid(), tag: 't', description: 'pending', is_done: false, difficulty: 2, created_at: nowSec },
+        { id: randomUUID(), tag: 't', description: 'pending', is_done: false, difficulty: 2, created_at: nowSec },
         ...Array.from({ length: 6 }, (_unused, i) => ({
-              id: uuid(),
+          id: randomUUID(),
           tag: 't',
           description: `done ${i}`,
           is_done: true,
@@ -45,7 +47,7 @@ test.describe('navigation does not replay the falling animation', () => {
       ],
     });
     const mkPage = (name: string, h: number, baseAgeDays: number) => ({
-          id: uuid(),
+      id: randomUUID(),
       name,
       hide_create_tower_button: false,
       keep_tasks_open: false,
@@ -55,7 +57,10 @@ test.describe('navigation does not replay the falling animation', () => {
     });
     // Page 0 ("Older") is the post-reload default; "Newer" is strictly more recent.
     const tree = { pages: [mkPage('Older', 0.05, 6), mkPage('Newer', 0.55, 1)] };
-        const token = uuid();
+    const token = randomUUID();
+
+    await page.addInitScript(
+      ({ tree, token }) => {
         localStorage.setItem('life-towers.token.v4', token);
         localStorage.setItem('life-towers.cache.v4.' + token, JSON.stringify(tree));
 
@@ -84,7 +89,7 @@ test.describe('navigation does not replay the falling animation', () => {
           true,
         );
       },
-      { nowSec, HOUR, DAY },
+      { tree, token },
     );
 
     await page.goto('/');