fix(website): extend calculator sliders to reach Scale plan

Extend write stops to 5B and retention stops to 25K GB so the
pricing calculator can recommend the Scale plan at higher usage.

Made-with: Cursor

Author: samwillis

website/src/components/pricing/PricingCalculator.vue

@@ -25,9 +25,10 @@ onMounted(() => {
 const WRITE_STOPS = [
   0, 100_000, 500_000, 1_000_000, 2_000_000, 5_000_000, 10_000_000, 25_000_000,
   50_000_000, 100_000_000, 250_000_000, 500_000_000, 1_000_000_000,
+  2_000_000_000, 5_000_000_000,
 ]
 const RETENTION_STOPS = [
-  0, 1, 5, 10, 25, 50, 100, 250, 500, 1_000, 2_500, 5_000,
+  0, 1, 5, 10, 25, 50, 100, 250, 500, 1_000, 2_500, 5_000, 10_000, 25_000,
 ]
 const SLIDER_MAX = 1000