feat: add offline agent marketplace foundation

src/tools/preset-switch.test.ts

@@ -92,6 +92,24 @@ describe('switchPresetOnDisk', () => {
     expect(result.message).toContain('no agent overrides');
   });
 
+  test('allows profile-only preset activation', () => {
+    const config: PluginConfig = {
+      presets: {
+        profiles: {
+          agents: {},
+          marketplace: {
+            profiles: { oracle: 'community/oracle-profile' },
+          },
+        },
+      },
+    };
+
+    const result = switchPresetOnDisk(tempDir, 'profiles', config);
+
+    expect(result.ok).toBe(true);
+    expect(result.presetName).toBe('profiles');
+  });
+
   test('switches preset and reports a reload-to-apply message', () => {
     const config: PluginConfig = {
       presets: {