feat: remove Copilot CLI shim and clean up worker file copying

extensions/copilot/script/postinstall.ts

@@ -61,6 +61,11 @@ const treeSitterGrammars: ITreeSitterGrammar[] = [
 
 const REPO_ROOT = path.join(__dirname, '..');
 
+async function removeCopilotCLIShim() {
+	const shimsPath = path.join(REPO_ROOT, 'node_modules', '@github', 'copilot', 'shims.txt');
+	await fs.promises.rm(shimsPath, { force: true }).catch(() => { /* ignore */ });
+}
+
 /**
  * @github/copilot/sdk/index.js depends on @github/copilot/worker/*.js files.
  * We need to copy these files into the sdk directory to ensure they are available at runtime.
@@ -173,6 +178,7 @@ async function main() {
 		'node_modules/@github/blackbird-external-ingest-utils/pkg/nodejs/external_ingest_utils_bg.wasm',
 	], 'dist');
 
+	await removeCopilotCLIShim();
 	await copyCopilotCliWorkerFiles();
 	await copyCopilotCliSharpFiles();
 	await copyCopilotCliDefinitionFiles();