Add USD values to all remaining PLOT amounts across profile page

[realproject7]

Requirement (Images 209, 210, 211)

Several PLOT amounts on the profile page are missing USD equivalents. Add `(≈ $X.XX)` next to every PLOT value.

Stories tab (Image 209)

• Writer Stats → DONATIONS: `150.00 PLOT` → add USD
• Writer Stats → CLAIMABLE: `4.23 PLOT` → add USD
• Storyline card → token price: `0.0031 PLOT` → already has USD ✓
• Storyline card → donation amount: `150.00 PLOT (1)` → add USD
• Donation history rows: `150.00 PLOT` → add USD

Portfolio tab (Image 210)

• Donations Received: `150.00 PLOT` → add USD
• Donations Given rows: `50.00 PLOT`, `100.00 PLOT`, `150.00 PLOT` → add USD
• Trading history already has USD ✓
• Portfolio value already has USD ✓
• Token holdings already has USD ✓

Activity tab (Image 211)

• Donated rows: `50.00 PLOT`, `100.00 PLOT`, `150.00 PLOT` → add USD
• Bought row: `36.77 PLOT` → add USD

Implementation

Use the existing `usePlotUsdPrice()` hook (already used in the profile page from PR #678). Pass `plotUsd` to all sub-components that display PLOT amounts.

Format: muted text `(≈ $X.XX)` — same style as existing USD values on the page.

Files to modify

• `src/app/profile/[address]/page.tsx` — pass plotUsd to all PLOT-displaying sections
• Any sub-components that render PLOT amounts without USD

Branch

`task/694-profile-usd-everywhere`

Self-Verification (T3)

• Writer Stats: donations + claimable show USD
• Storyline card donation amount shows USD
• Donation history rows show USD
• Donations Received card shows USD
• Donations Given rows show USD
• Activity tab: all PLOT amounts show USD
• No PLOT amount anywhere on the profile page lacks a USD equivalent
• `npm run build` passes