refactor: consolidate scriptDownloader to single JavaScript implementation

- Updated scriptDownloader.js to support multi-repository downloads using repository_url from script metadata
- Added getScriptDiff() and generateDiff() methods to JavaScript version
- Updated scripts.ts router to explicitly import .js version
- Removed duplicate TypeScript version (scriptDownloader.ts)
- All functionality now consolidated in single JavaScript file used by both Next.js API routes and Node.js server-side code

src/server/api/routers/scripts.ts

@@ -3,7 +3,7 @@ import { createTRPCRouter, publicProcedure } from "~/server/api/trpc";
 import { scriptManager } from "~/server/lib/scripts";
 import { githubJsonService } from "~/server/services/githubJsonService";
 import { localScriptsService } from "~/server/services/localScripts";
-import { scriptDownloaderService } from "~/server/services/scriptDownloader";
+import { scriptDownloaderService } from "~/server/services/scriptDownloader.js";
 import { AutoSyncService } from "~/server/services/autoSyncService";
 import type { ScriptCard } from "~/types/script";