**Description** Deploy and test the `EventRegistry` contract on Base Sepolia using Foundry. **Tasks** - [ ] Write test cases in `/test/EventRegistry.t.sol` - [ ] Test event creation, ownership restriction, and ticket updates - [ ] Deploy contract via Foundry script (`forge script`) - [ ] Verify deployment on BaseScan **Deliverables** - [ ] All tests pass (`forge test`) - [ ] Contract deployed and verified on Base Sepolia **Labels:** `backend`, `testing`, `deployment`