### 🧪 Add mocked integration tests for full deposit flow

**Overview**  
Create an end-to-end mocked test for deposit flow across client, wallet, transaction builder, and vault modules.

**Requirements**
- Mock contract call creation
- Mock wallet signing
- Mock RPC submission
- Verify final response shape

**Acceptance Criteria**
- Full SDK deposit flow is tested
- No real network calls are required
- Test can run in CI

**Labels**: testing, integration