Improve error handling in check script

- Distinguish ENOENT from EACCES and other I/O errors instead of
  treating all failures as 'missing'
- Log errors to stderr with descriptive messages
- Validate JSON files parse correctly
- Detect empty files
- Report total failure count on exit

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: cem

scripts/check.mjs

@@ -13,14 +13,37 @@ const required = [
 let failed = 0;
 for (const file of required) {
   try {
-    await readFile(new URL(`../${file}`, import.meta.url), "utf8");
+    const content = await readFile(new URL(`../${file}`, import.meta.url), "utf8");
+    if (!content.trim()) {
+      failed += 1;
+      console.error(`empty ${file}`);
+      continue;
+    }
+    if (file.endsWith(".json")) {
+      try {
+        JSON.parse(content);
+      } catch (parseErr) {
+        failed += 1;
+        console.error(`invalid json ${file}: ${parseErr.message}`);
+        continue;
+      }
+    }
     console.log(`ok ${file}`);
-  } catch {
+  } catch (err) {
     failed += 1;
-    console.log(`missing ${file}`);
+    if (err.code === "ENOENT") {
+      console.error(`missing ${file}`);
+    } else if (err.code === "EACCES") {
+      console.error(`permission denied ${file}: ${err.message}`);
+    } else {
+      console.error(`error reading ${file}: ${err.message}`);
+    }
   }
 }
 
-if (failed) process.exit(1);
+if (failed) {
+  console.error(`\n${failed} file(s) failed checks`);
+  process.exit(1);
+}
 console.log("graphite incubator check passed");