[#682] Sub-2: Merge Reader Dashboard into Profile Portfolio tab

[realproject7]

Parent: #682
Depends on: #683

Scope

Replace the Profile page's basic Portfolio tab with the full Reader Dashboard content, then remove the standalone `/reader` page.

Requirements

1. Profile Portfolio tab — full reader dashboard

Move content from `src/app/dashboard/reader/page.tsx` into the profile page's Portfolio tab:

• Portfolio summary (from `ReaderPortfolio` component): total value, per-holding with 24h price change, best pick
• Trading history: paginated trades with storyline titles, buy/sell badges, USD values
• Donation history: paginated donations

2. Viewing someone else's profile

Portfolio tab shows their public data:

• Their token holdings (on-chain, public) — read-only
• Their trading history (on-chain, public) — read-only
• No donation history (or keep if useful — up to T3)

3. Remove /reader page

• Delete `src/app/dashboard/reader/page.tsx` (or the reader dashboard route)
• Add redirect: `/reader` → `/profile/[connected-address]?tab=portfolio`

Files to modify

• `src/app/profile/[address]/page.tsx` — replace Portfolio tab content
• `src/app/dashboard/reader/page.tsx` — delete after migration
• `src/components/ReaderPortfolio.tsx` — may need to accept `address` prop (currently uses connected wallet)
• Move/refactor reader-specific components as needed

Branch

`task/684-merge-reader-dashboard`

Self-Verification (T3)

• Profile Portfolio tab shows full portfolio + trading history (own profile)
• Other users' profiles show their holdings + trades (read-only, public data)
• Pagination works for trading history and donations
• USD values display correctly
• `/reader` redirects to profile
• `npm run build` passes