feat: orchestration harness, selective install, observer improvements

scripts/lib/install/apply.js

@@ -0,0 +1,23 @@
+'use strict';
+
+const fs = require('fs');
+
+const { writeInstallState } = require('../install-state');
+
+function applyInstallPlan(plan) {
+  for (const operation of plan.operations) {
+    fs.mkdirSync(require('path').dirname(operation.destinationPath), { recursive: true });
+    fs.copyFileSync(operation.sourcePath, operation.destinationPath);
+  }
+
+  writeInstallState(plan.installStatePath, plan.statePreview);
+
+  return {
+    ...plan,
+    applied: true,
+  };
+}
+
+module.exports = {
+  applyInstallPlan,
+};