Set metadataBase in every app so OG/social image URLs are absolute

[rep0x]

🎯 Goal

Set metadataBase in every Next.js app across the fleet so social/OG and Twitter card image URLs resolve to absolute URLs. Today it's unset everywhere, so each build prints:

⚠️ metadataBase property in metadata export is not set ... using "http://localhost:3000"

and the canonical/OG image URLs in production HTML are wrong (localhost-relative), which breaks link unfurls on Slack/iMessage/social.

🧭 Background

Surfaced during the @mind-studio/ui 0.7.0 brand-refresh Wave 2 rollout (ui#29), which added opengraph-image.tsx + manifest.ts to many apps. The OG routes render fine, but without metadataBase Next can't build absolute URLs for them. It predates the brand work (landing had the same warning) — calling it out as its own fleet follow-up rather than scope-creeping the brand PRs.

🔧 Fix (per app)

In each app's root src/app/layout.tsx metadata export, set metadataBase to the app's canonical production origin, read from env with a sensible default:

export const metadata: Metadata = {
  metadataBase: new URL(
    process.env.NEXT_PUBLIC_SITE_URL ?? "https://<app>.mindpods.org",
  ),
  // ...existing title/description/etc.
};

• Use each app's real production host (e.g. drive.mindpods.org, slides.mindpods.org, dock.mindpods.org, apex mindpods.org for landing).
• Prefer an env var (NEXT_PUBLIC_SITE_URL or the existing convention in src/lib/links.ts where present) so non-prod deploys resolve correctly.
• Verify the build warning is gone and the emitted <meta property="og:image"> is an absolute URL.

📋 Apps to update

All Next.js consumers — at minimum the ones with OG/manifest routes: landing, drive, slides, chat, calendar, builder, videos, shell (+ any other app that ships opengraph-image/manifest). Apps without OG metadata can be skipped or done for consistency.

✅ Acceptance criteria

• Every app sets metadataBase to its canonical origin (env-driven where possible).
• No metadataBase ... not set warning in any app's build.
• Production OG/Twitter image URLs are absolute and unfurl correctly.

🔗 Related

• Fleet rollout: adopt @mind-studio/ui brand refresh (weave logo + per-app wordmark + typography + ./brand) across all consumers ui#29 — the brand-refresh rollout that surfaced this.