Subscription cost tracker for teams

Build a tool that tracks a company's SaaS subscriptions.

Core features:
1. Add subscription: vendor, cost, cycle, renewal date, owner
2. Alert 14 days before renewal
3. Dashboard: monthly burn, top vendors, unused seats
4. Attach contracts (PDF) and cancellation URL

Data: vendors, subscriptions, alerts.
Must-haves: currency conversion, RLS by workspace, weekly digest email.