feat: Refactor transaction management with nanostores and convert components to React

- Added @nanostores/react for state management.
- Created AccountSummary component to display account balance.
- Replaced AddTransactionForm.astro with AddTransactionForm.tsx for better state handling.
- Introduced TransactionTable.tsx for displaying transactions with edit/delete functionality.
- Updated Sidebar.astro and MainContent.astro to use React components.
- Implemented transactionStore.ts for managing current account ID and transaction editing state.
- Removed obsolete AddTransactionForm.astro and related scripts.
- Enhanced error handling and loading states in transaction forms.
This fixes issues #7, #8, #9, #10, #11

package.json

@@ -13,9 +13,11 @@
   "dependencies": {
     "@astrojs/cloudflare": "^12.5.1",
     "@astrojs/react": "^4.2.5",
+    "@nanostores/react": "^1.0.0",
     "@types/react": "^19.1.2",
     "@types/react-dom": "^19.1.2",
     "astro": "^5.7.5",
+    "nanostores": "^1.0.1",
     "react": "^19.1.0",
     "react-dom": "^19.1.0"
   },