chore: clean up dead UI code and regenerate schema

- Remove non-functional search bar, notifications and settings buttons from header
- Remove leftover console.log and unused useAttrs import in sidebar
- Remove unused scoped CSS in computers/index.vue (Tailwind-only template)
- Regenerate database/schema.ts after running migrations locally
- Ignore .serena/ local tooling directory
- Refresh package-lock.json after npm install

.gitignore

@@ -28,6 +28,7 @@ coverage
 .fleet
 .idea
 .vscode
+.serena
 *.swp
 *.swo