ci: format fetch-spec-types output with prettier

The nightly update-spec-types workflow is failing because lefthook's
pre-push hook (added in #1003) runs `pnpm run lint:all`, which rejects
the freshly-fetched spec.types.ts for not matching prettier style.

Format the output via prettier's Node API using the project config
before writing it to disk. This also reduces nightly PR diffs to only
semantic changes, not formatting noise.

Author: felixweinberger

scripts/fetch-spec-types.ts

@@ -1,6 +1,7 @@
 import { writeFileSync } from 'node:fs';
 import { dirname, join } from 'node:path';
 import { fileURLToPath } from 'node:url';
+import * as prettier from 'prettier';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
@@ -72,9 +73,12 @@ async function main() {
         // Combine header and content
         const fullContent = header + specContent;
 
-        // Write to file
+        // Format with prettier using the project's config so the output passes lint
         const outputPath = join(PROJECT_ROOT, 'packages', 'core', 'src', 'types', 'spec.types.ts');
-        writeFileSync(outputPath, fullContent, 'utf-8');
+        const prettierConfig = await prettier.resolveConfig(outputPath);
+        const formatted = await prettier.format(fullContent, { ...prettierConfig, filepath: outputPath });
+
+        writeFileSync(outputPath, formatted, 'utf-8');
 
         console.log('Successfully updated packages/core/src/types/spec.types.ts');
     } catch (error) {