feat: add gemini install target

scripts/lib/install-targets/gemini-project.js

@@ -0,0 +1,10 @@
+const { createInstallTargetAdapter } = require('./helpers');
+
+module.exports = createInstallTargetAdapter({
+  id: 'gemini-project',
+  target: 'gemini',
+  kind: 'project',
+  rootSegments: ['.gemini'],
+  installStatePathSegments: ['ecc-install-state.json'],
+  nativeRootRelativePath: '.gemini',
+});