PlotLink: Update og:image, favicon, and Farcaster manifest with new assets

[realproject7]

Summary

New brand assets have been added to /public:

• favicon.png
• icon.png
• og-image.png
• splash.png
• wide-banner.png

Update all metadata references to use these assets.

Changes needed

1. src/app/layout.tsx — Add to the metadata export:

• openGraph.images → /og-image.png
• icons → /favicon.png (or /icon.png)
• twitter.images → /og-image.png

2. public/.well-known/farcaster.json — Update:

• iconUrl → verify it points to /icon.png (currently https://plotlink.xyz/icon.png — confirm correct)
• splashBackgroundUrl or imageUrl → /splash.png if applicable
• Add ogImageUrl or coverImageUrl if the manifest supports it

3. HTML favicon — Ensure <link rel="icon"> is set. Next.js App Router can auto-detect /app/favicon.ico or use the metadata API.

Assets available

public/
  favicon.png
  icon.png
  og-image.png
  splash.png
  wide-banner.png
  plotlink-logo-symbol.svg

Acceptance Criteria

• og:image meta tag renders /og-image.png on all pages
• Favicon displays favicon.png in browser tabs
• Farcaster manifest references correct icon and splash assets
• twitter:image meta tag set
• npm run typecheck passes

Labels

agent/T3, plotlink, ui, infra