Get tier matrix

Returns the full tier comparison matrix — limits, pricing, and feature availability. Public endpoint, no authentication required. Each entry has a purchasable flag: only Developer is self-serve as of the 2026-07 pricing reframe — Live and Analytics are grandfathered-only (existing subscribers) and Enterprise was always sales-led. A synthetic custom entry (purchasable: false, no tier counterpart in the subscription DB) represents the sales-led plan that now covers what Live/Analytics/Enterprise used to sell — contact sales@racehooks.io.