mplemented issue requirements

[amoduenechojo]

Title:
enhance(deliveries): integrate local landmark data into workflow cards

Summary
This change enhances the delivery workflow cards to display localized landmark references alongside standard street addresses. The UI now renders landmark information in a visually distinct, wrapped badge-style block so drivers can quickly identify navigation cues in complex street layouts.

What changed
Updated the workflow card layout to support an optional landmark field
Added clear visual emphasis for landmarks to improve readability
Ensured the layout remains responsive on smaller screens without text overflow
Kept the implementation aligned with the existing component → hook → service architecture
Added test coverage for both landmark-present and null-landmark scenarios
Verification
Unit tests for the workflow cards were run successfully

Closes #149

Title:
enhance(escrow): implement volatility slippage warnings for fiat to crypto previews

Summary
This PR adds a clear slippage warning experience for fiat-to-XLM payment previews when the quoted NGN/XLM rate becomes highly volatile. It helps users spot sudden FX movement before confirming a payment and blocks confirmation until they explicitly acknowledge critical volatility.

What changed
Added a warning state for slippage above the 2% threshold
Added a stronger critical warning for slippage above the 5% threshold
Required explicit checkbox acknowledgment before proceeding when slippage is critical
Kept the implementation aligned with the component → hook → service architecture
Wired the warning logic to the live FX rate flow from the backend-backed service layer
Verification
Ran: npm test -- --runTestsByPath FiatXlmPreview.test.tsx fiatXlmSlippageService.test.ts --runInBand
Result: 2/2 test suites passed, 30/30 tests passed

Closes #168