Refactor InstalledScriptsTab for code style consistency

Updated InstalledScriptsTab.tsx to use double quotes and consistent formatting throughout the file. Improved type annotations, code readability, and standardized state initialization and mutation usage. No functional changes were made; this is a style and maintainability refactor.

src/server/services/githubJsonService.ts

@@ -398,7 +398,6 @@ export class GitHubJsonService {
     const filesToSync: GitHubFile[] = [];
     
     for (const ghFile of githubFiles) {
-      const slug = ghFile.name.replace('.json', '');
       const localFilePath = join(this.localJsonDirectory!, ghFile.name);
       
       let needsSync = false;