fix(manacore): improve dashboard layout polish

- Remove unnecessary wrapper div in WidgetContainer
- Increase grid gap from gap-4 to gap-5 for breathing room
- Add auto-rows-fr for equal row heights
- Add min-h on widget content so empty widgets aren't tiny
- Change default layout to 3 equal columns (small)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/context/apps/web/src/routes/offline/+page.ts

@@ -0,0 +1 @@
+export const prerender = true;