Merchant Dashboard Endpoints

**Description:**
APIs for merchants to view/manage their trades, rates, profile, and KYC status.

**Acceptance Criteria:**
- Endpoint to list merchant’s trades and statuses
- Endpoint to update rates and profile
- Endpoint to view KYC status and resubmit if needed

**Subtasks:**
- [ ] Trades listing endpoint
- [ ] Rates/profile update endpoint
- [ ] KYC status endpoint
