Tidy up Trading History layout on Reader Dashboard

[realproject7]

Problem

The Trading History section on the Reader Dashboard (/reader) is poorly formatted on mobile:

1. Token amounts overflow — "2728254.80 tokens" wraps awkwardly, breaking the row layout
2. Inconsistent row heights — some rows are single-line, others wrap into 2-3 lines
3. Numbers not formatted — raw numbers like "2728254.80" should be formatted (e.g., "2,728,254.80" or shortened to "2.73M")
4. Story reference unclear — "Story [#4] Add CI pipeline for lint and type-check #43" should ideally show the storyline title
5. Date truncated — "Mar 27" is fine but "Mar" alone is confusing
6. Scientific notation — "5e-6 PLOT" is not user-friendly, show "< 0.001 PLOT" or similar

Requirements

Redesign the Trading History rows to match the clean card-based style used on the profile page trust dashboard. Each trade should be a clean row or card with:

• Type badge: Buy (green) / Sell (red) — small colored badge
• Story title: Full storyline title instead of "Story [#4] Add CI pipeline for lint and type-check #43" (or truncated if long)
• Date: Formatted consistently (e.g., "Mar 27, 2026")
• Token amount: Formatted with locale separators or shortened (2.73M tokens)
• PLOT cost: Formatted nicely, avoid scientific notation
• Tx link: Keep the external link arrow

Mobile-first layout — rows should not overflow or wrap awkwardly on small screens. Consider a stacked layout for mobile:

Buy · Straton                    83.81 PLOT
2,728,254 tokens · Mar 27, 2026       ↗

Files to modify

• src/app/reader/page.tsx or wherever the Reader Dashboard trading history is rendered

Branch

task/622-trading-history-layout

Acceptance criteria

• Trade rows don't overflow on mobile
• Token amounts formatted (locale separators or abbreviated)
• No scientific notation — use "< 0.001" or similar
• Story title shown instead of "Story [#4] Add CI pipeline for lint and type-check #43" where possible
• Dates formatted consistently
• Matches PlotLink terminal aesthetic
• Build passes