[FE-44] Admin membership plans management (/admin/plans) + public /pricing page

[yusuftomilola]

Overview

Admins need a UI to create and manage membership tiers — the pricing plans that members subscribe to. Without this page, plans can only be managed via direct database manipulation.

Context

• Admin pages pattern: frontend/app/admin/members/page.tsx
• Depends on BE-55 for membership plan CRUD endpoints
• Member subscriptions are visible in the existing member detail view

Tasks

• Create /admin/plans page — table listing all membership plans with columns: Name, Price, Billing Cycle, Features count, Active Subscribers, Status (Active/Inactive), Display Order
• "Create Plan" button opens a form modal:
  • Name, description (textarea)
  • Price (NGN input, converted to kobo on submit)
  • Billing cycle dropdown: Monthly / Quarterly / Yearly
  • Features: add/remove chip list (press Enter to add a feature bullet)
  • Booking hours included (0 = unlimited)
  • Guest passes per month
  • Display order (integer, for controlling sort on the public plans page)
  • Active toggle
• Row actions: "Edit" (pre-filled modal), "Archive" (sets inactive — shown only if no active subscribers)
• Subscriber count is a clickable link to /admin/members?plan=:id
• Create a public-facing /pricing page showing active plans in display-order, with a "Subscribe" CTA for each plan (calls POST /membership-plans/:id/subscribe)
• Create useGetMembershipPlans, useCreatePlan, useUpdatePlan React Query hooks

Files to Modify / Create

• New: frontend/app/admin/plans/page.tsx
• New: frontend/app/pricing/page.tsx
• New: frontend/lib/react-query/hooks/membership/

[1sraeliteX]

Gm, I would like to work on this