[P1] Fee row on payment confirmation needs visual prominence

[islandbitcoin]

Filed by Lori (app audit). Design + copy change.

File: app/screens/send/send-confirmation.tsx (approx — Nick to confirm)

Problem: Fee row has same visual weight as other data rows. This is the PMF moment — Flash charges nothing vs WU J$1,500-2,000.

Changes:

• Fee label: Fee → Flash fee:
• Fee value: brand green (#3ab54a), font-weight bold
• Add secondary line in small gray text: Western Union charges ~J$1,800 for this transfer
• Secondary line only shows when transfer > $10 USD equivalent

Screenshots: https://drive.google.com/drive/folders/10gCqvwfIV1pb6Bv-Z4E6KWkvPMnOBgdR

[linear]

ENG-149

[Nodirbek75]

[chengyixu]

Hi! I'd like to work on this issue.

Approach: The fix is straightforward: update send-confirmation.tsx to apply brand green (#3ab54a) with font-weight bold to the fee value, change the label text from 'Fee' to 'Flash fee:', and add a small gray secondary line showing the Western Union comparison text. This is a targeted UI-only change with no logic impact.

Timeline: 1-2 days

I've done React Native UI work on fintech apps and understand the importance of this PMF moment — making the zero-fee advantage visually unmissable at the payment confirmation step. Happy to share a mockup before starting.

GitHub: @chengyixu

[patoo0x]

📋 Definition of Done — 💰 40,000 sats

Expected Behavior After Fix:

• Fee label reads "Flash fee:" (not just "Fee")
• Fee value is displayed in brand green (#3ab54a) and bold
• A secondary line in small gray text reads: "Western Union charges ~J$1,800 for this transfer"
• The secondary line only appears when the transfer is > $10 USD equivalent
• Layout looks clean on both iOS and Android, all screen sizes
• No visual regressions on the rest of the send confirmation screen

Deliverables:

• PR against main referencing this issue (closes #561)
• Screenshots: before and after on both iOS and Android
• Screen recording showing the fee row on a transfer above and below $10 USD equivalent
• Lightning address provided in your first comment on this issue

Review Gate:

• All existing tests pass
• Nick signs off
• Dread final approval

Payment: 40,000 sats via Lightning on merge.
See CONTRIBUTING.md for full details.