Convert backend/web from submodule to regular directory

backend/web/.gitignore

@@ -0,0 +1,28 @@
+node_modules
+
+# Output
+.output
+.vercel
+.netlify
+.wrangler
+/.svelte-kit
+/build
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Env
+.env
+.env.*
+!.env.example
+!.env.test
+
+# Vite
+vite.config.js.timestamp-*
+vite.config.ts.timestamp-*
+# SQLite
+*.db
+*.db.wal
+
+.fontello