- /admin/subscriptions: shows revenue stats, projected revenue (1mo/3mo/6mo/1yr),
upcoming renewal events, and recent subscription history
- /admin/subscriptions/add: form to create subscriptions by user email/ID
with product selection, frequency override, and initial state
- Fix bug in createSubscription() where $status was undefined parameter
- Add model methods: getRecent, getUpcoming, getTotalRevenue, getActiveCount,
getProjectedRevenue, getSubscriptionProducts
- Add nav link on admin dashboard
Closes#17