feat: add community marketplace for custom widgets and CSS

Adds a PocketBase-backed marketplace where users can share custom widgets
and CSS themes. Includes a Docusaurus storefront with GitHub OAuth login,
submission/voting/comments, and a PocketBase SQL view that computes author
names, vote counts, and comment counts without fragile hooks. The Next.js
app gets a modal browser for one-click install from the marketplace plus
clipboard paste-to-import on the custom widgets pages.

apps/docs/tsconfig.json

@@ -16,6 +16,9 @@
     "isolatedModules": true,
     "jsx": "preserve",
     "incremental": true,
+    "paths": {
+      "@/*": ["./src/*"]
+    }
   },
   "include": [
     "**/*.ts",