backend: implement team/group DevCard API for hackathon teams

[ShantKhatri]

Summary

Product doc section 5.4 describes Group / Team Cards — a team or open source project creates a shared DevCard showing all members. Implement the backend API for team cards.

Tasks

• design Prisma schema:
  • Team: id, name, slug, description, avatarUrl, ownerId, createdAt.
  • TeamMember: teamId, userId, role (owner/member), joinedAt.
• create apps/backend/src/routes/teams.ts:
  • POST /api/teams — create a team (authenticated).
  • GET /api/teams/:slug — public team profile with member list (public).
  • POST /api/teams/:slug/members — invite a member by username (owner only).
  • DELETE /api/teams/:slug/members/:userId — remove member (owner only, or self-remove).
  • PUT /api/teams/:slug — update team name, description, avatar (owner only).
  • DELETE /api/teams/:slug — delete team (owner only).
• the public team view endpoint should return member profiles in the same PlatformLink[] shape as individual public profiles.
• add a team QR code endpoint that encodes devcard.dev/team/:slug.
• register routes in apps/backend/src/app.ts.
• write tests covering ownership guards, member management, and public read.

Acceptance Criteria

• teams can be created, populated with members, and queried publicly.
• only the owner can manage membership.
• self-removal (leaving the team) works for any member.
• tests pass covering all ownership boundary conditions.

Difficulty

advanced — requires multi-role authorization design and relational schema with ownership semantics.

[Harxhit]

Hi,
I’d love to work on this Team Cards feature (Product doc section 5.4).

Just to keep you updated on my current assignments:

I have already submitted a PR for issue #21.
I have also completed issue #30 locally and am planning to push it on the 15th to claim the points.

I'm happy to take it up.