feat(admin): implement pricing overrides for plans and update pricing logic

packages/api-contract/src/plan.ts

@@ -33,7 +33,24 @@ export const planRulesV1Schema = z.object({
   }),
 })
 
-export const planRulesSchema = z.discriminatedUnion('version', [planRulesV1Schema])
+export const planPriceOverrideSchema = z.object({
+  amount: z.number().nonnegative(),
+  currency: z.string().length(3),
+})
+
+export const planRulesV2Schema = planRulesV1Schema.extend({
+  version: z.literal('v2'),
+  pricing: z
+    .object({
+      overrides: z.record(z.string(), planPriceOverrideSchema),
+    })
+    .optional(),
+})
+
+export const planRulesSchema = z.discriminatedUnion('version', [
+  planRulesV1Schema,
+  planRulesV2Schema,
+])
 
 export const planSchema = z.object({
   code: z.string().trim().min(1).max(10),
@@ -60,12 +77,14 @@ export const planWithFeaturesSchema = z.object({
   code: z.string().trim().min(1).max(10),
   name: z.string().trim().min(1).max(30),
   price: z.number().nonnegative(),
+  currency: z.string().length(3),
   features: planFeatureFlagsSchema,
   limits: planLimitsSchema,
 })
 
 export type PlanFeatureFlags = z.infer<typeof planFeatureFlagsSchema>
 export type PlanRulesV1 = z.infer<typeof planRulesV1Schema>
+export type PlanRulesV2 = z.infer<typeof planRulesV2Schema>
 export type PlanRules = z.infer<typeof planRulesSchema>
 export type Plan = z.infer<typeof planSchema>
 export type PlanSummary = z.infer<typeof planSummarySchema>