fix: harden install planning and sync tracked catalogs

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

@@ -4,14 +4,28 @@ const {
   createFlatRuleOperations,
   createInstallTargetAdapter,
   createManagedScaffoldOperation,
+  normalizeRelativePath,
 } = require('./helpers');
 
+const SUPPORTED_SOURCE_PREFIXES = ['rules', 'commands', 'agents', 'skills', '.agents', 'AGENTS.md'];
+
+function supportsAntigravitySourcePath(sourceRelativePath) {
+  const normalizedPath = normalizeRelativePath(sourceRelativePath);
+  return SUPPORTED_SOURCE_PREFIXES.some(prefix => (
+    normalizedPath === prefix || normalizedPath.startsWith(`${prefix}/`)
+  ));
+}
+
 module.exports = createInstallTargetAdapter({
   id: 'antigravity-project',
   target: 'antigravity',
   kind: 'project',
   rootSegments: ['.agent'],
   installStatePathSegments: ['ecc-install-state.json'],
+  supportsModule(module) {
+    const paths = Array.isArray(module && module.paths) ? module.paths : [];
+    return paths.length > 0;
+  },
   planOperations(input, adapter) {
     const modules = Array.isArray(input.modules)
       ? input.modules
@@ -30,7 +44,9 @@ module.exports = createInstallTargetAdapter({
 
     return modules.flatMap(module => {
       const paths = Array.isArray(module.paths) ? module.paths : [];
-      return paths.flatMap(sourceRelativePath => {
+      return paths
+        .filter(supportsAntigravitySourcePath)
+        .flatMap(sourceRelativePath => {
         if (sourceRelativePath === 'rules') {
           return createFlatRuleOperations({
             moduleId: module.id,
@@ -62,8 +78,8 @@ module.exports = createInstallTargetAdapter({
           ];
         }
 
-        return [adapter.createScaffoldOperation(module.id, sourceRelativePath, planningInput)];
-      });
+          return [adapter.createScaffoldOperation(module.id, sourceRelativePath, planningInput)];
+        });
     });
   },
 });