### 🧪 Add tests for vault hook actions

**Overview**  
The `useVault` hook should be tested for deposit, withdraw, claim rewards, and balance fetch behavior.

**Requirements**
- Mock Protox SDK methods
- Test loading states
- Test success and error responses
- Validate state updates

**Acceptance Criteria**
- Vault hook has meaningful coverage
- SDK calls are mocked correctly
- Tests cover user-facing states

**Labels**: testing, vault