chore: migrate to Bun, update deps and add Nuxt Fonts

- Replace pnpm with Bun (bun.lock, remove pnpm-lock.yaml)
- Add @nuxt/fonts module and configure Iconify icons
- Add NUXT_OG_IMAGE_SECRET for multi-instance OG image signing
- Update dependencies to latest versions
- Simplify Tailwind font configuration
- Add trustedDependencies and overrides for unhead packages

tailwind.config.ts

@@ -20,14 +20,7 @@ export default {
         "text-muted": "rgb(104, 120, 152)",
       },
       fontFamily: {
-        sans: [
-          '"Inter"',
-          "system-ui",
-          "-apple-system",
-          "BlinkMacSystemFont",
-          '"Segoe UI"',
-          "sans-serif",
-        ],
+        sans: ['"Inter"', "ui-sans-serif", "system-ui", "sans-serif"],
       },
       spacing: {
         "safe-x": "max(1rem, env(safe-area-inset-left))",