Fechamento de Caixa - Tauri 2 initial commit

- Storage: SQLite local via rusqlite
- Supabase: REST API via reqwest
- Printer: USB ESC/POS for TM-T20
- Frontend: vanilla HTML (form-v9.3 ported)
- Build: GitHub Actions for Linux/Windows/macOS

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "fechamento-caixa",
+  "version": "1.0.0",
+  "description": "Fechamento de Caixa — O Frangão",
+  "scripts": {
+    "dev": "tauri dev",
+    "build": "tauri build",
+    "tauri": "tauri"
+  },
+  "devDependencies": {
+    "@tauri-apps/cli": "^2"
+  },
+  "dependencies": {}
+}