feat(plugins): merge Skill management into plugins

tests/unit/pi-product-artifact.test.ts

@@ -93,7 +93,6 @@ async function bundledResourceFixture({ schemaVersion = 1, includeSdkAssets = tr
   };
   await mkdir(path.join(pluginRoot, 'com.makelore'), { recursive: true });
   await mkdir(path.join(pluginRoot, 'skills', 'example'), { recursive: true });
-  await mkdir(path.join(sourceResources, 'coding-skills', 'agent-browser'), { recursive: true });
   await writeFile(path.join(pluginRoot, 'plugin.json'), JSON.stringify({
     name: 'example.plugin',
     version: '1.0.0',
@@ -106,7 +105,6 @@ async function bundledResourceFixture({ schemaVersion = 1, includeSdkAssets = tr
     await writeFile(path.join(pluginRoot, 'skills', 'example', 'assets', 'sdk.ts'), 'export {};\n');
     await writeFile(path.join(pluginRoot, 'skills', 'example', 'assets', 'sdk.js'), 'export {};\n');
   }
-  await writeFile(path.join(sourceResources, 'coding-skills', 'agent-browser', 'SKILL.md'), '# Browser\n');
   const resourcesDirectory = path.join(root, 'packaged');
   await cp(sourceResources, path.join(resourcesDirectory, 'resources'), { recursive: true });
   return {
@@ -192,7 +190,7 @@ describe('final Pi product artifact verification', () => {
     });
   });
 
-  it('proves bundled plugin manifests, Skills, SDK assets, catalog, and core resources', async () => {
+  it('proves bundled plugin manifests, Skills, SDK assets, and the absence of standalone Skill resources', async () => {
     const fixture = await bundledResourceFixture();
     await expect(verifyBundledCodingPluginResources(fixture)).resolves.toMatchObject({
       root: 'resources/coding-plugins',
@@ -209,11 +207,27 @@ describe('final Pi product artifact verification', () => {
         tools: ['example_read'],
       }],
       catalog: { adapters: ['example-adapter'], tools: ['example_read'], packagedInAsar: true },
-      coreResources: { root: 'resources/coding-skills', skills: ['agent-browser'] },
+      coreResources: { root: null, files: [], skills: [] },
       result: 'pass',
     });
   });
 
+  it('rejects any source or packaged standalone Skill directory', async () => {
+    const sourceFixture = await bundledResourceFixture();
+    await mkdir(path.join(sourceFixture.projectRoot, 'resources', 'coding-skills', 'legacy'), {
+      recursive: true,
+    });
+    await expect(verifyBundledCodingPluginResources(sourceFixture))
+      .rejects.toThrow('Standalone coding Skill resources must not be bundled');
+
+    const packagedFixture = await bundledResourceFixture();
+    await mkdir(path.join(packagedFixture.resourcesDirectory, 'resources', 'coding-skills'), {
+      recursive: true,
+    });
+    await expect(verifyBundledCodingPluginResources(packagedFixture))
+      .rejects.toThrow('Standalone coding Skill resources must not be bundled');
+  });
+
   it('accepts schema-2 hosted plugins whose implementation has no client SDK assets', async () => {
     const fixture = await bundledResourceFixture({ schemaVersion: 2, includeSdkAssets: false });
     await expect(verifyBundledCodingPluginResources(fixture)).resolves.toMatchObject({