fix: resolve Prettier markdown code block parsing errors

- Fix syntax errors in skills markdown files (.github/skills, .opencode/skills)
- Change typescript to tsx for code blocks with JSX
- Replace ellipsis (...) in array examples with valid syntax
- Separate CSS from TypeScript into distinct code blocks
- Convert JavaScript object examples to valid JSON in docs
- Fix enum definitions with proper comma separation

.opencode/skills/vercel-react-best-practices/rules/js-length-check-first.md

@@ -16,7 +16,7 @@ In real-world applications, this optimization is especially valuable when the co
 ```typescript
 function hasChanges(current: string[], original: string[]) {
   // Always sorts and joins, even when lengths differ
-  return current.sort().join() !== original.sort().join()
+  return current.sort().join() !== original.sort().join();
 }
 ```
 
@@ -28,21 +28,22 @@ Two O(n log n) sorts run even when `current.length` is 5 and `original.length` i
 function hasChanges(current: string[], original: string[]) {
   // Early return if lengths differ
   if (current.length !== original.length) {
-    return true
+    return true;
   }
   // Only sort when lengths match
-  const currentSorted = current.toSorted()
-  const originalSorted = original.toSorted()
+  const currentSorted = current.toSorted();
+  const originalSorted = original.toSorted();
   for (let i = 0; i < currentSorted.length; i++) {
     if (currentSorted[i] !== originalSorted[i]) {
-      return true
+      return true;
     }
   }
-  return false
+  return false;
 }
 ```
 
 This new approach is more efficient because:
+
 - It avoids the overhead of sorting and joining the arrays when lengths differ
 - It avoids consuming memory for the joined strings (especially important for large arrays)
 - It avoids mutating the original arrays