refactor(#353): profile centralize links nip05

[DSanich]

Summary

• Added a centralized profile-link utility to build profile URLs in one place (NIP-05-aware when metadata is present, deterministic npub fallback otherwise).
• Replaced ad-hoc profile URL construction across key entry points (video cards, fullscreen video, reactions, mentions, notifications, search, leaderboard, dialogs, and navigation).
• Removed legacy temporary profile-link logic in VideoCard and aligned routing helpers to use the shared builder.

Avoid naming corporate partners, customers, or other sensitive external brands in this PR title or body. Use generic descriptors unless a maintainer explicitly approves the public reference.

Motivation

• Prevent profile-route drift by centralizing link generation logic instead of building routes inline in multiple components.
• Keep navigation behavior stable for users with and without NIP-05 metadata while making routing updates safer going forward.
• Reduce maintenance overhead and improve confidence with focused test coverage around the shared link builder.

Related Issue

• Closes refactor(profile): centralize profile URL building with NIP-05-aware routing #353

Testing

• npm run test
• Manual verification completed
• npx vitest run src/lib/profileLinks.test.ts src/components/VideoCard.test.tsx src/pages/SearchPage.test.tsx
• npx tsc --noEmit

Visuals

• UI change with screenshots/video attached
• No visual change
• Visuals and text avoid sensitive external brand or partner names unless explicitly approved

[github-actions]

🚀 Preview Deployment

Property	Value
Preview URL	https://08f54b58.divine-web-fm8.pages.dev
Commit	5a8cd41
Branch	refactor/353-profile-centralize-links-nip05