chore(build): consolidate packaging inputs and build output layout (#299)

scripts/package-bun-source.test.ts

@@ -4,6 +4,9 @@ import fs from 'node:fs/promises';
 import os from 'node:os';
 import path from 'node:path';
 import {
+  DEFAULT_MANIFEST_PATH,
+  DEFAULT_PACKAGE_JSON_PATH,
+  DEFAULT_RUNTIME_MANIFEST_PATH,
   downloadArchive,
   parseRegisteredRepositories,
   parseSourceManifest,
@@ -67,10 +70,26 @@ describe('Bun corresponding-source manifest', () => {
     });
   });
 
+  test('default manifest paths resolve to aligned checked-in manifests', async () => {
+    const [manifestText, runtimeManifestText, packageJsonText] = await Promise.all([
+      fs.readFile(DEFAULT_MANIFEST_PATH, 'utf8'),
+      fs.readFile(DEFAULT_RUNTIME_MANIFEST_PATH, 'utf8'),
+      fs.readFile(DEFAULT_PACKAGE_JSON_PATH, 'utf8'),
+    ]);
+
+    expect(() =>
+      validateRuntimeAlignment(
+        parseSourceManifest(JSON.parse(manifestText)),
+        JSON.parse(packageJsonText),
+        JSON.parse(runtimeManifestText),
+      ),
+    ).not.toThrow();
+  });
+
   test('rejects stale runtime or package-manager pins', async () => {
     const manifest = parseSourceManifest(
       JSON.parse(
-        await fs.readFile(path.join(projectRoot, 'build/bun-source-manifest.json'), 'utf8'),
+        await fs.readFile(path.join(projectRoot, 'packaging/bun/bun-source-manifest.json'), 'utf8'),
       ),
     );
     const runtimeManifest = {
@@ -100,7 +119,7 @@ describe('Bun corresponding-source manifest', () => {
   test('rejects drift in CMake dependency and WebKit pins', async () => {
     const manifest = parseSourceManifest(
       JSON.parse(
-        await fs.readFile(path.join(projectRoot, 'build/bun-source-manifest.json'), 'utf8'),
+        await fs.readFile(path.join(projectRoot, 'packaging/bun/bun-source-manifest.json'), 'utf8'),
       ),
     );
     const registrations = manifest.sources