[#682] Sub-1: Merge Writer Dashboard into Profile Stories tab

[realproject7]

Parent: #682

Scope

Replace the Profile page's basic Stories tab with the full Writer Dashboard content, then remove the standalone `/writer` page.

Requirements

1. Profile Stories tab — full writer dashboard

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

• Storyline cards with: plots, views, created date, donations, deadline countdown
• Token price + TVL (with USD values from PR [#672] Add USD values across dashboards #678)
• Royalties + Claim button — only when `isOwnProfile`
• Genre/Language editing — only when `isOwnProfile`
• Donation history per storyline — only when `isOwnProfile`

2. Viewing someone else's profile

Stories tab shows their storylines read-only:

• Storyline cards with plots, views, created date
• Token price + TVL
• No claim button, no genre edit, no donation details

3. Fix wallet card BigInt(0) rendering bug

In the wallet identity card, `{claimedRoyalties && claimedRoyalties > BigInt(0) && (...)}` renders "0" because `BigInt(0)` is falsy but React renders it as text.

Fix: `{claimedRoyalties != null && claimedRoyalties > BigInt(0) && (...)}`

4. Remove /writer page

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

Files to modify

• `src/app/profile/[address]/page.tsx` — replace Stories tab content
• `src/app/dashboard/writer/page.tsx` — delete after migration
• Move/refactor writer-specific components as needed
• Fix BigInt(0) bug in wallet card

Branch

`task/683-merge-writer-dashboard`

Self-Verification (T3)

• Profile Stories tab shows full writer dashboard content (own profile)
• Claim royalties button works on own profile
• Genre/language editing works on own profile
• Other users' profiles show storylines read-only (no claim, no edit)
• Wallet card no longer shows stray "0"
• `/writer` redirects to profile
• USD values still display correctly
• `npm run build` passes