fix: rename pm2 worker and invoke tsx directly instead of npm

pm2 fork mode require()s the resolved script rather than spawning a
shell, and on o2switch `npm` resolves to CloudLinux's bash npm_wrapper,
so pm2 crashed instantly (SyntaxError) and restart-looped forever.
Point pm2 at tsx's real ESM entry (node_modules/tsx/dist/cli.mjs)
instead. Also renames the pm2 process to video-downloader-worker.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

ecosystem.config.cjs

@@ -1,9 +1,9 @@
 module.exports = {
   apps: [
     {
-      name: 'ombrora-worker',
-      script: 'npm',
-      args: 'run worker',
+      name: 'video-downloader-worker',
+      script: 'node_modules/tsx/dist/cli.mjs',
+      args: 'worker/index.ts',
       cwd: __dirname,
       autorestart: true,
       max_restarts: 10,