Align admin optional-services billing UI with runtimes and bill RAM proportionally.

Split optional pricing vs deploy defaults and move custom domain to its own card; parse Mi as decimal GB so fractional memory scales linearly with per-GB rates. Deploy wizard hides env and optional services for WordPress and sanitizes create payloads.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/billing/pricing-catalog.service.ts

@@ -580,7 +580,7 @@ export class PricingCatalogService implements OnModuleInit {
       case PricingResourceType.CPU_PER_CORE:
         return `CPU (${quantity.toFixed(2)} core)`;
       case PricingResourceType.MEMORY_PER_GB:
-        return `Memory (${quantity.toFixed(2)} GB)`;
+        return `Memory (${quantity.toFixed(3)} GB billable)`;
       case PricingResourceType.STORAGE_PER_GB:
         return `Storage (${quantity} GB)`;
       default:
@@ -616,12 +616,19 @@ export class PricingCatalogService implements OnModuleInit {
     return parseFloat(cpu) || 0;
   }
 
+  /**
+   * Billable memory quantity for rates labeled "per GB".
+   * Uses decimal GB so fractional Mi scales linearly (e.g. 500Mi → 0.5 × per-GB price).
+   * Gi values are treated as GB-sized billing units (1Gi → 1 unit).
+   */
   parseMemoryToGb(memory: string): number {
     if (!memory) return 0;
-    if (memory.endsWith('Gi')) return parseFloat(memory);
-    if (memory.endsWith('Mi')) return parseFloat(memory) / 1024;
-    if (memory.endsWith('Ki')) return parseFloat(memory) / (1024 * 1024);
-    return parseFloat(memory) / (1024 * 1024 * 1024);
+    const m = memory.trim();
+    if (m.endsWith('Gi')) return parseFloat(m) || 0;
+    if (m.endsWith('Mi')) return (parseFloat(m) || 0) / 1000;
+    if (m.endsWith('Ki')) return (parseFloat(m) || 0) / 1_000_000;
+    const n = parseFloat(m);
+    return Number.isFinite(n) ? n / (1024 * 1024 * 1024) : 0;
   }
 
   private async upsertRuntimeRate(runtime: AppRuntime, row: PricingRateRow) {