feat(dashboard): close legacy parity gaps

packages/api-contracts/tests/contracts.test.ts

@@ -17,6 +17,7 @@ import {
   MediaResponseSchema,
   MediaSyncStatusSchema,
   MessagesResponseSchema,
+  ProcessedPostsResponseSchema,
   StatsResponseSchema,
   StrategyPerformanceResponseSchema,
   SubredditPerformanceResponseSchema,
@@ -103,6 +104,13 @@ describe('dashboard endpoint contracts', () => {
     expect(TimersResponseSchema.safeParse({ hourlyResetAt: 'later' }).success).toBe(false);
     expect(ActivityResponseSchema.safeParse([{ ...activity, type: 'bogus' }]).success).toBe(false);
     expect(MessagesResponseSchema.safeParse([{ id: '1' }]).success).toBe(false);
+    const processedPost = {
+      id: 'post-1', subreddit: 'example', author: 'alice', title: 'Example',
+      imageUrl: null, imageAnalysis: null, generatedMessage: 'Hello',
+      processedAt: 1_700_000_000_000, messageSent: true, error: null,
+    };
+    expect(ProcessedPostsResponseSchema.safeParse([processedPost]).success).toBe(true);
+    expect(ProcessedPostsResponseSchema.safeParse([{ ...processedPost, messageSent: 'yes' }]).success).toBe(false);
   });
 
   it('validates each analytics response shape', () => {