fix: keep browser asset build package-local

extensions/browser/scripts/build-copilot-runtime.mjs

@@ -1,14 +1,30 @@
 #!/usr/bin/env node
+import fs from "node:fs/promises";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 import { build } from "esbuild";
-import { writeGeneratedTextAsset } from "../../../scripts/lib/generated-text-asset.mjs";
 
 const modulePath = fileURLToPath(import.meta.url);
 const pluginDir = path.resolve(path.dirname(modulePath), "..");
 const repoRoot = path.resolve(pluginDir, "../..");
 const outfile = path.join(pluginDir, "chrome-extension", "modules", "copilot-runtime.js");
 
+async function writeCopilotRuntimeIfChanged(filePath, contents) {
+  try {
+    if ((await fs.readFile(filePath, "utf8")) === contents) {
+      return false;
+    }
+  } catch (error) {
+    if (error?.code !== "ENOENT") {
+      throw error;
+    }
+  }
+
+  await fs.mkdir(path.dirname(filePath), { recursive: true });
+  await fs.writeFile(filePath, contents, "utf8");
+  return true;
+}
+
 /** Builds the copilot runtime without rewriting an identical generated asset. */
 export async function buildCopilotRuntime(params = {}) {
   const buildImpl = params.build ?? build;
@@ -31,7 +47,7 @@ export async function buildCopilotRuntime(params = {}) {
     throw new Error("esbuild did not produce the Browser copilot runtime bundle");
   }
 
-  return writeGeneratedTextAsset(outputPath, outputFile.text);
+  return writeCopilotRuntimeIfChanged(outputPath, outputFile.text);
 }
 
 if (process.argv[1] === modulePath) {