refactor: move studio to frontends workspace

- Move studio from root to frontends/studio/
- Add owner-tools frontend for live blog admin UI
- Add shared ui component library
- Set up npm workspaces for frontends
- Add enhanced code block extension for editor

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontends/owner-tools/uno.config.ts

@@ -0,0 +1,31 @@
+import { defineConfig, presetWind4, presetIcons } from 'unocss'
+import { theme, shortcuts } from '@writekit/ui/uno.config'
+
+export default defineConfig({
+  presets: [
+    presetWind4(),
+    presetIcons({
+      scale: 1.2,
+      cdn: 'https://esm.sh/',
+      extraProperties: {
+        'display': 'inline-block',
+        'vertical-align': 'middle',
+      },
+    }),
+  ],
+  theme,
+  shortcuts: {
+    ...shortcuts,
+    'label-text': 'block text-sm font-medium text-text mb-1.5',
+  },
+  preflights: [
+    {
+      getCSS: () => `
+        @keyframes wk-slide-in {
+          from { transform: translateX(-100%); }
+          to { transform: translateX(0); }
+        }
+      `,
+    },
+  ],
+})