Restore native boot scheduling without an extra core request

frontend/shell-consistency.test.js

@@ -32,7 +32,7 @@ test('assets.json describes the complete existing shell exactly once with eager
   const { groups } = JSON.parse(readFileSync(join(__dirname, 'assets.json'), 'utf8'));
   const described = new Set();
   for (const [name, group] of Object.entries(groups)) {
-    assert.equal(group.contract, 1, `${name} initial contract`);
+    assert.equal(group.contract, name === 'core' ? 2 : 1, `${name} contract (core boot packing changed)`);
     assert.equal(typeof group.eager, 'boolean');
     for (const asset of group.files) {
       assert.ok(!described.has(asset), `${asset} has one group`);
@@ -100,12 +100,15 @@ test('classic first-visit style preload is discovered before the head loader wit
 });
 
 
-test('the eager cache bootstrap stays last and retains app.js in core and legacy shell',()=>{
+test('the last core script owns boot without an extra request or unsafe stale packing',()=>{
  const {groups}=JSON.parse(readFileSync(join(__dirname,'assets.json'),'utf8'));
- assert.ok(groups.core.files.includes('/app-bootstrap.js'));
+ assert.equal(groups.core.contract,2,'old core packing cannot fall back without the loader');
  assert.ok(groups.core.files.includes('/app.js'));
- assert.ok(listed.has('/app-bootstrap.js')&&listed.has('/app.js'));
- assert.ok(html.indexOf('src="app-bootstrap.js"')>html.indexOf('src="section-rail.js"'));
+ assert.ok(groups.core.files.includes('/section-rail.js'));
+ assert.equal(groups.core.files.includes('/app-bootstrap.js'),false);
+ assert.equal(listed.has('/app-bootstrap.js'),false);
+ const scripts=[...html.matchAll(/<script src="([^"]+)"/g)].map(m=>m[1]);
+ assert.equal(scripts.at(-1),'section-rail.js');
  assert.ok(html.includes("'sha256-__APP_SCRIPT_HASH__'"));
- assert.ok(readFileSync(join(__dirname,'lazy.js'),'utf8').includes("api.appResponse=(async()=>"));
+ assert.ok(readFileSync(join(__dirname,'section-rail.js'),'utf8').includes('root.AppBootstrap={ready}'));
 });