Feat/workspace template

[CarmenDou]

Summary by cubic

Adds a Notion-style collaborative workspace template under workspace/ and registers it in the marketplace. Ships a Next.js app with auth, RLS-backed multi-workspaces (with switcher and default workspace bootstrap), nested pages with rich-text editing, invites, and public sharing.

• New template: workspace/ (Next.js 16 + React 19 + Tailwind v4)

• Auth: email/password + OAuth via @insforge/sdk (no SMTP required)

• Workspaces: multi-workspace with switcher; owner/editor/viewer roles via RLS

• Pages: nested tree, BlockNote editor, image uploads to workspace-files, autosave with conflict handling

• Sharing: per-page public links and revocation; invite links with role selection and accept flow

• Settings: profile, members, invites list, leave/delete workspace

• Database: workspaces, workspace_members, pages, invites with RLS and RPCs

• Docs: README and LICENSE

• Registry: added workspace entry with refreshed cover and demo URL

• Migration

  • Create storage bucket: from workspace/, run npm run setup (creates public workspace-files)
  • Apply schema: run workspace/migrations/20260525060055_db-init.sql
  • Configure env: copy workspace/.env.example → .env.local and set NEXT_PUBLIC_INSFORGE_URL, NEXT_PUBLIC_INSFORGE_ANON_KEY, NEXT_PUBLIC_APP_URL
  • Install and run: cd workspace && npm install && npm run dev

^{Written for commit 8fe5b9c. Summary will update on new commits. Review in cubic}

[jwfing]

LGTM, approved.