merge: preserve project and user Codex configuration source 3253

scripts/lib/install-targets/codex-home.js

@@ -1,6 +1,10 @@
-const { HOME_INSTALL_EXCLUDED_SOURCE_PATHS, createInstallTargetAdapter } = require('./helpers');
+const fs = require('fs');
+const path = require('path');
+const {
+  HOME_INSTALL_EXCLUDED_SOURCE_PATHS, createInstallTargetAdapter, createManagedOperation,
+} = require('./helpers');
 
-module.exports = createInstallTargetAdapter({
+const adapter = createInstallTargetAdapter({
   id: 'codex-home',
   target: 'codex',
   kind: 'home',
@@ -9,3 +13,35 @@ module.exports = createInstallTargetAdapter({
   nativeRootRelativePath: '.codex',
   excludedSourcePaths: HOME_INSTALL_EXCLUDED_SOURCE_PATHS,
 });
+
+const USER_REFERENCE = '.codex/user-config.example.toml';
+
+module.exports = Object.freeze({
+  ...adapter,
+  planOperations(input = {}) {
+    // Delegate the existing platform filters, exclusions and scaffold metadata.
+    return adapter.planOperations(input).flatMap(operation => {
+      if (operation.sourceRelativePath !== '.codex') return [operation];
+      // Abstract metadata-only plans need no filesystem. A selected real source
+      // must not silently fall back to the narrower project config.
+      if (input.repoRoot && fs.existsSync(input.repoRoot)) {
+        let stat;
+        try {
+          stat = fs.lstatSync(path.join(input.repoRoot, USER_REFERENCE));
+        } catch (error) {
+          if (error.code !== 'ENOENT') throw error;
+        }
+        if (!stat || !stat.isFile() || stat.isSymbolicLink()) {
+          throw new Error('Codex user reference must exist as a regular file');
+        }
+      }
+      // The planner materializes these operations, then keeps the last copy per
+      // destination before preview/state/apply. Only the user reference survives.
+      return [operation, createManagedOperation({
+        moduleId: operation.moduleId,
+        sourceRelativePath: USER_REFERENCE,
+        destinationPath: path.join(operation.destinationPath, 'config.toml'),
+      })];
+    });
+  },
+});