chore: configure codex build environment

scripts/verify-dist.mjs

@@ -0,0 +1,33 @@
+import { existsSync, readFileSync } from "node:fs";
+import { join } from "node:path";
+
+const distDir = "dist";
+const manifestPath = join(distDir, "manifest.json");
+
+function fail(message) {
+  console.error(message);
+  process.exitCode = 1;
+}
+
+if (!existsSync(distDir)) {
+  fail("Missing dist/ output directory. Run vite build first.");
+} else if (!existsSync(manifestPath)) {
+  fail("Missing dist/manifest.json. The built folder is not loadable as a Chrome extension.");
+} else {
+  const manifest = JSON.parse(readFileSync(manifestPath, "utf8"));
+  const popup = manifest.action?.default_popup;
+
+  if (manifest.manifest_version !== 3) {
+    fail("dist/manifest.json must be a Manifest V3 extension manifest.");
+  }
+
+  if (!popup) {
+    fail("dist/manifest.json is missing action.default_popup.");
+  } else if (!existsSync(join(distDir, popup))) {
+    fail(`dist/${popup} does not exist.`);
+  }
+}
+
+if (!process.exitCode) {
+  console.log("dist/ is ready to load as an unpacked Chrome extension.");
+}