feat: add campaign configuration controls

convex/schema.ts

@@ -135,8 +135,10 @@ export default defineSchema({
       v.literal("monthly"),
     ),
     status: campaignStatus,
+    countryCode: v.optional(v.string()),
+    country: v.optional(v.string()),
     lastRunAt: v.optional(v.number()),
-    nextRunAt: v.optional(v.number()),
+    nextRunAt: v.optional(v.union(v.number(), v.null())),
     createdAt: v.number(),
     updatedAt: v.number(),
   })
@@ -276,6 +278,7 @@ export default defineSchema({
   })
     .index("by_status", ["status"])
     .index("by_type_and_status", ["type", "status"])
+    .index("by_campaignId_and_updatedAt", ["campaignId", "updatedAt"])
     .index("by_campaignId_and_status", ["campaignId", "status"])
     .index("by_auditId", ["auditId"]),