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/async-parallel.md

@@ -12,17 +12,13 @@ When async operations have no interdependencies, execute them concurrently using
 **Incorrect (sequential execution, 3 round trips):**
 
 ```typescript
-const user = await fetchUser()
-const posts = await fetchPosts()
-const comments = await fetchComments()
+const user = await fetchUser();
+const posts = await fetchPosts();
+const comments = await fetchComments();
 ```
 
 **Correct (parallel execution, 1 round trip):**
 
 ```typescript
-const [user, posts, comments] = await Promise.all([
-  fetchUser(),
-  fetchPosts(),
-  fetchComments()
-])
+const [user, posts, comments] = await Promise.all([fetchUser(), fetchPosts(), fetchComments()]);
 ```