feat: add shared dashboard API contracts

packages/api-contracts/src/activity.ts

@@ -0,0 +1,21 @@
+import { z } from 'zod';
+
+export const ActivityTypeSchema = z.union([
+  z.literal('sent'),
+  z.literal('skipped'),
+  z.literal('response'),
+  z.literal('error'),
+  z.literal('info'),
+  z.literal('debug'),
+]);
+
+export const ActivityItemSchema = z.strictObject({
+  timestamp: z.number(),
+  type: ActivityTypeSchema,
+  message: z.string(),
+  recipient: z.string().optional(),
+  imageUrl: z.string().optional(),
+});
+
+export const ActivityResponseSchema = z.array(ActivityItemSchema);
+export type ActivityItem = z.infer<typeof ActivityItemSchema>;