diff --git a/.gitignore b/.gitignore
index d532e728..57be5377 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,6 +19,11 @@ coverage
 .nyc_output
 .coverage
 
+# Test artifacts - flyer-images/ is a runtime directory
+# Test fixtures are stored in src/tests/assets/ instead
+flyer-images/
+test-output.txt
+
 # Editor directories and files
 .vscode/*
 !.vscode/extensions.json
@@ -31,3 +36,4 @@ coverage
 *.sw?
 Thumbs.db
 .claude
+nul
diff --git a/CLAUDE.md b/CLAUDE.md
index d19997ec..44b8045f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -20,6 +20,26 @@ npm run test:unit  # Run unit tests only
 npm run test:integration  # Run integration tests (requires DB/Redis)
 ```
 
+### Running Tests via Podman (from Windows host)
+
+The command to run unit tests in the Linux container via podman:
+
+```bash
+podman exec -it flyer-crawler-dev npm run test:unit
+```
+
+The command to run integration tests in the Linux container via podman:
+
+```bash
+podman exec -it flyer-crawler-dev npm run test:integration
+```
+
+For running specific test files:
+
+```bash
+podman exec -it flyer-crawler-dev npm test -- --run src/hooks/useAuth.test.tsx
+```
+
 ### Why Linux Only?
 
 - Path separators: Code uses POSIX-style paths (`/`) which may break on Windows
diff --git a/src/tests/integration/admin.integration.test.ts b/src/tests/integration/admin.integration.test.ts
index 6385263a..5df8036a 100644
--- a/src/tests/integration/admin.integration.test.ts
+++ b/src/tests/integration/admin.integration.test.ts
@@ -59,7 +59,7 @@ describe('Admin API Routes Integration Tests', () => {
       const response = await request
         .get('/api/admin/stats')
         .set('Authorization', `Bearer ${adminToken}`);
-      const stats = response.body;
+      const stats = response.body.data;
       // DEBUG: Log response if it fails expectation
       if (response.status !== 200) {
         console.error('[DEBUG] GET /api/admin/stats failed:', response.status, response.body);
@@ -75,7 +75,7 @@ describe('Admin API Routes Integration Tests', () => {
         .get('/api/admin/stats')
         .set('Authorization', `Bearer ${regularUserToken}`);
       expect(response.status).toBe(403);
-      const errorData = response.body;
+      const errorData = response.body.error;
       expect(errorData.message).toBe('Forbidden: Administrator access required.');
     });
   });
@@ -85,7 +85,7 @@ describe('Admin API Routes Integration Tests', () => {
       const response = await request
         .get('/api/admin/stats/daily')
         .set('Authorization', `Bearer ${adminToken}`);
-      const dailyStats = response.body;
+      const dailyStats = response.body.data;
       expect(dailyStats).toBeDefined();
       expect(Array.isArray(dailyStats)).toBe(true);
       // We just created users in beforeAll, so we should have data
@@ -100,7 +100,7 @@ describe('Admin API Routes Integration Tests', () => {
         .get('/api/admin/stats/daily')
         .set('Authorization', `Bearer ${regularUserToken}`);
       expect(response.status).toBe(403);
-      const errorData = response.body;
+      const errorData = response.body.error;
       expect(errorData.message).toBe('Forbidden: Administrator access required.');
     });
   });
@@ -112,7 +112,7 @@ describe('Admin API Routes Integration Tests', () => {
       const response = await request
         .get('/api/admin/corrections')
         .set('Authorization', `Bearer ${adminToken}`);
-      const corrections = response.body;
+      const corrections = response.body.data;
       expect(corrections).toBeDefined();
       expect(Array.isArray(corrections)).toBe(true);
     });
@@ -122,7 +122,7 @@ describe('Admin API Routes Integration Tests', () => {
         .get('/api/admin/corrections')
         .set('Authorization', `Bearer ${regularUserToken}`);
       expect(response.status).toBe(403);
-      const errorData = response.body;
+      const errorData = response.body.error;
       expect(errorData.message).toBe('Forbidden: Administrator access required.');
     });
   });
@@ -132,7 +132,7 @@ describe('Admin API Routes Integration Tests', () => {
       const response = await request
         .get('/api/admin/brands')
         .set('Authorization', `Bearer ${adminToken}`);
-      const brands = response.body;
+      const brands = response.body.data;
       expect(brands).toBeDefined();
       expect(Array.isArray(brands)).toBe(true);
       // Even if no brands exist, it should return an array.
@@ -145,7 +145,7 @@ describe('Admin API Routes Integration Tests', () => {
         .get('/api/admin/brands')
         .set('Authorization', `Bearer ${regularUserToken}`);
       expect(response.status).toBe(403);
-      const errorData = response.body;
+      const errorData = response.body.error;
       expect(errorData.message).toBe('Forbidden: Administrator access required.');
     });
   });
@@ -238,7 +238,7 @@ describe('Admin API Routes Integration Tests', () => {
         .put(`/api/admin/corrections/${testCorrectionId}`)
         .set('Authorization', `Bearer ${adminToken}`)
         .send({ suggested_value: '300' });
-      const updatedCorrection = response.body;
+      const updatedCorrection = response.body.data;
 
       // Assert: Verify the API response and the database state.
       expect(updatedCorrection.suggested_value).toBe('300');
@@ -274,7 +274,7 @@ describe('Admin API Routes Integration Tests', () => {
   });
 
   describe('DELETE /api/admin/users/:id', () => {
-    it('should allow an admin to delete another user\'s account', async () => {
+    it("should allow an admin to delete another user's account", async () => {
       // Act: Call the delete endpoint as an admin.
       const targetUserId = regularUser.user.user_id;
       const response = await request
@@ -296,10 +296,14 @@ describe('Admin API Routes Integration Tests', () => {
       // The service throws ValidationError, which maps to 400.
       // We also allow 403 in case authorization middleware catches it in the future.
       if (response.status !== 400 && response.status !== 403) {
-         console.error('[DEBUG] Self-deletion failed with unexpected status:', response.status, response.body);
+        console.error(
+          '[DEBUG] Self-deletion failed with unexpected status:',
+          response.status,
+          response.body,
+        );
       }
       expect([400, 403]).toContain(response.status);
-      expect(response.body.message).toMatch(/Admins cannot delete their own account/);
+      expect(response.body.error.message).toMatch(/Admins cannot delete their own account/);
     });
 
     it('should return 404 if the user to be deleted is not found', async () => {
diff --git a/src/tests/integration/ai.integration.test.ts b/src/tests/integration/ai.integration.test.ts
index f95ec9c7..ffa7ede3 100644
--- a/src/tests/integration/ai.integration.test.ts
+++ b/src/tests/integration/ai.integration.test.ts
@@ -67,7 +67,7 @@ describe('AI API Routes Integration Tests', () => {
       .post('/api/ai/check-flyer')
       .set('Authorization', `Bearer ${authToken}`)
       .attach('image', Buffer.from('content'), 'test.jpg');
-    const result = response.body;
+    const result = response.body.data;
     expect(response.status).toBe(200);
     // The backend is stubbed to always return true for this check
     expect(result.is_flyer).toBe(true);
@@ -78,7 +78,7 @@ describe('AI API Routes Integration Tests', () => {
       .post('/api/ai/extract-address')
       .set('Authorization', `Bearer ${authToken}`)
       .attach('image', Buffer.from('content'), 'test.jpg');
-    const result = response.body;
+    const result = response.body.data;
     expect(response.status).toBe(200);
     expect(result.address).toBe('not identified');
   });
@@ -88,7 +88,7 @@ describe('AI API Routes Integration Tests', () => {
       .post('/api/ai/extract-logo')
       .set('Authorization', `Bearer ${authToken}`)
       .attach('images', Buffer.from('content'), 'test.jpg');
-    const result = response.body;
+    const result = response.body.data;
     expect(response.status).toBe(200);
     expect(result).toEqual({ store_logo_base_64: null });
   });
@@ -98,7 +98,7 @@ describe('AI API Routes Integration Tests', () => {
       .post('/api/ai/quick-insights')
       .set('Authorization', `Bearer ${authToken}`)
       .send({ items: [{ item: 'test' }] });
-    const result = response.body;
+    const result = response.body.data;
     // DEBUG: Log response if it fails expectation
     if (response.status !== 200 || !result.text) {
       console.log('[DEBUG] POST /api/ai/quick-insights response:', response.status, response.body);
@@ -112,7 +112,7 @@ describe('AI API Routes Integration Tests', () => {
       .post('/api/ai/deep-dive')
       .set('Authorization', `Bearer ${authToken}`)
       .send({ items: [{ item: 'test' }] });
-    const result = response.body;
+    const result = response.body.data;
     // DEBUG: Log response if it fails expectation
     if (response.status !== 200 || !result.text) {
       console.log('[DEBUG] POST /api/ai/deep-dive response:', response.status, response.body);
@@ -126,7 +126,7 @@ describe('AI API Routes Integration Tests', () => {
       .post('/api/ai/search-web')
       .set('Authorization', `Bearer ${authToken}`)
       .send({ query: 'test query' });
-    const result = response.body;
+    const result = response.body.data;
     // DEBUG: Log response if it fails expectation
     if (response.status !== 200 || !result.text) {
       console.log('[DEBUG] POST /api/ai/search-web response:', response.status, response.body);
@@ -174,7 +174,7 @@ describe('AI API Routes Integration Tests', () => {
       console.log('[DEBUG] POST /api/ai/plan-trip response:', response.status, response.body);
     }
     expect(response.status).toBe(500);
-    const errorResult = response.body;
+    const errorResult = response.body.error;
     expect(errorResult.message).toContain('planTripWithMaps');
   });
 
diff --git a/src/tests/integration/auth.integration.test.ts b/src/tests/integration/auth.integration.test.ts
index 970aecf1..4056e446 100644
--- a/src/tests/integration/auth.integration.test.ts
+++ b/src/tests/integration/auth.integration.test.ts
@@ -44,10 +44,14 @@ describe('Authentication API Integration', () => {
     const response = await request
       .post('/api/auth/login')
       .send({ email: testUserEmail, password: TEST_PASSWORD, rememberMe: false });
-    const data = response.body;
+    const data = response.body.data;
 
     if (response.status !== 200) {
-      console.error('[DEBUG] Login failed:', response.status, JSON.stringify(data, null, 2));
+      console.error(
+        '[DEBUG] Login failed:',
+        response.status,
+        JSON.stringify(response.body, null, 2),
+      );
     }
 
     // Assert that the API returns the expected structure
@@ -69,7 +73,7 @@ describe('Authentication API Integration', () => {
       .post('/api/auth/login')
       .send({ email: adminEmail, password: wrongPassword, rememberMe: false });
     expect(response.status).toBe(401);
-    const errorData = response.body;
+    const errorData = response.body.error;
     expect(errorData.message).toBe('Incorrect email or password.');
   });
 
@@ -82,7 +86,7 @@ describe('Authentication API Integration', () => {
       .post('/api/auth/login')
       .send({ email: nonExistentEmail, password: anyPassword, rememberMe: false });
     expect(response.status).toBe(401);
-    const errorData = response.body;
+    const errorData = response.body.error;
     // Security best practice: the error message should be identical for wrong password and wrong email
     // to prevent user enumeration attacks.
     expect(errorData.message).toBe('Incorrect email or password.');
@@ -103,8 +107,8 @@ describe('Authentication API Integration', () => {
 
     // Assert 1: Check that the registration was successful and the returned profile is correct.
     expect(registerResponse.status).toBe(201);
-    const registeredProfile = registerResponse.body.userprofile;
-    const registeredToken = registerResponse.body.token;
+    const registeredProfile = registerResponse.body.data.userprofile;
+    const registeredToken = registerResponse.body.data.token;
     expect(registeredProfile.user.email).toBe(email);
     expect(registeredProfile.avatar_url).toBeNull(); // The API should return null for the avatar_url.
 
@@ -117,7 +121,7 @@ describe('Authentication API Integration', () => {
       .set('Authorization', `Bearer ${registeredToken}`);
 
     expect(profileResponse.status).toBe(200);
-    expect(profileResponse.body.avatar_url).toBeNull();
+    expect(profileResponse.body.data.avatar_url).toBeNull();
   });
 
   it('should successfully refresh an access token using a refresh token cookie', async () => {
@@ -137,7 +141,7 @@ describe('Authentication API Integration', () => {
 
     // Assert: Check for a successful response and a new access token.
     expect(response.status).toBe(200);
-    const data = response.body;
+    const data = response.body.data;
     expect(data.token).toBeTypeOf('string');
   });
 
@@ -152,7 +156,7 @@ describe('Authentication API Integration', () => {
 
     // Assert: Check for a 403 Forbidden response.
     expect(response.status).toBe(403);
-    const data = response.body;
+    const data = response.body.error;
     expect(data.message).toBe('Invalid or expired refresh token.');
   });
 
diff --git a/src/tests/integration/budget.integration.test.ts b/src/tests/integration/budget.integration.test.ts
index 36930962..2a5abce9 100644
--- a/src/tests/integration/budget.integration.test.ts
+++ b/src/tests/integration/budget.integration.test.ts
@@ -45,7 +45,13 @@ describe('Budget API Routes Integration Tests', () => {
       `INSERT INTO public.budgets (user_id, name, amount_cents, period, start_date) 
        VALUES ($1, $2, $3, $4, $5) 
        RETURNING *`,
-      [testUser.user.user_id, budgetToCreate.name, budgetToCreate.amount_cents, budgetToCreate.period, budgetToCreate.start_date],
+      [
+        testUser.user.user_id,
+        budgetToCreate.name,
+        budgetToCreate.amount_cents,
+        budgetToCreate.period,
+        budgetToCreate.start_date,
+      ],
     );
     testBudget = budgetRes.rows[0];
     createdBudgetIds.push(testBudget.budget_id);
@@ -67,9 +73,9 @@ describe('Budget API Routes Integration Tests', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(response.status).toBe(200);
-      const budgets: Budget[] = response.body;
+      const budgets: Budget[] = response.body.data;
       expect(budgets).toBeInstanceOf(Array);
-      expect(budgets.some(b => b.budget_id === testBudget.budget_id)).toBe(true);
+      expect(budgets.some((b) => b.budget_id === testBudget.budget_id)).toBe(true);
     });
 
     it('should return 401 if user is not authenticated', async () => {
@@ -82,4 +88,4 @@ describe('Budget API Routes Integration Tests', () => {
   it.todo('should allow an authenticated user to update their own budget');
   it.todo('should allow an authenticated user to delete their own budget');
   it.todo('should return spending analysis for the authenticated user');
-});
\ No newline at end of file
+});
diff --git a/src/tests/integration/flyer.integration.test.ts b/src/tests/integration/flyer.integration.test.ts
index 438caee9..14cd0547 100644
--- a/src/tests/integration/flyer.integration.test.ts
+++ b/src/tests/integration/flyer.integration.test.ts
@@ -44,7 +44,7 @@ describe('Public Flyer API Routes Integration Tests', () => {
     );
 
     const response = await request.get('/api/flyers');
-    flyers = response.body;
+    flyers = response.body.data;
   });
 
   afterAll(async () => {
@@ -60,7 +60,7 @@ describe('Public Flyer API Routes Integration Tests', () => {
     it('should return a list of flyers', async () => {
       // Act: Call the API endpoint using the client function.
       const response = await request.get('/api/flyers');
-      const flyers: Flyer[] = response.body;
+      const flyers: Flyer[] = response.body.data;
       expect(response.status).toBe(200);
       expect(flyers).toBeInstanceOf(Array);
 
@@ -86,7 +86,7 @@ describe('Public Flyer API Routes Integration Tests', () => {
 
       // Act: Fetch items for the first flyer.
       const response = await request.get(`/api/flyers/${testFlyer.flyer_id}/items`);
-      const items: FlyerItem[] = response.body;
+      const items: FlyerItem[] = response.body.data;
 
       expect(response.status).toBe(200);
       expect(items).toBeInstanceOf(Array);
@@ -110,7 +110,7 @@ describe('Public Flyer API Routes Integration Tests', () => {
 
       // Act: Fetch items for all available flyers.
       const response = await request.post('/api/flyers/items/batch-fetch').send({ flyerIds });
-      const items: FlyerItem[] = response.body;
+      const items: FlyerItem[] = response.body.data;
       expect(response.status).toBe(200);
       expect(items).toBeInstanceOf(Array);
       // The total number of items should be greater than or equal to the number of flyers (assuming at least one item per flyer).
@@ -128,7 +128,7 @@ describe('Public Flyer API Routes Integration Tests', () => {
 
       // Act
       const response = await request.post('/api/flyers/items/batch-count').send({ flyerIds });
-      const result = response.body;
+      const result = response.body.data;
 
       // Assert
       expect(result.count).toBeTypeOf('number');
diff --git a/src/tests/integration/gamification.integration.test.ts b/src/tests/integration/gamification.integration.test.ts
index 70aad6ba..3dcb2d17 100644
--- a/src/tests/integration/gamification.integration.test.ts
+++ b/src/tests/integration/gamification.integration.test.ts
@@ -260,7 +260,7 @@ describe('Gamification Flow Integration Test', () => {
 
     // --- Act 4: Fetch the leaderboard ---
     const leaderboardResponse = await request.get('/api/achievements/leaderboard');
-    const leaderboard: LeaderboardUser[] = leaderboardResponse.body;
+    const leaderboard: LeaderboardUser[] = leaderboardResponse.body.data;
 
     // --- Assert 3: Verify the user is on the leaderboard with points ---
     const userOnLeaderboard = leaderboard.find((u) => u.user_id === testUser.user.user_id);
@@ -315,7 +315,7 @@ describe('Gamification Flow Integration Test', () => {
       // --- Assert ---
       // 6. Check for a successful response.
       expect(response.status).toBe(200);
-      const newFlyer: Flyer = response.body;
+      const newFlyer: Flyer = response.body.data;
       expect(newFlyer).toBeDefined();
       expect(newFlyer.flyer_id).toBeTypeOf('number');
       createdFlyerIds.push(newFlyer.flyer_id); // Add for cleanup.
diff --git a/src/tests/integration/notification.integration.test.ts b/src/tests/integration/notification.integration.test.ts
index 51c69097..cd1aa871 100644
--- a/src/tests/integration/notification.integration.test.ts
+++ b/src/tests/integration/notification.integration.test.ts
@@ -62,7 +62,7 @@ describe('Notification API Routes Integration Tests', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(response.status).toBe(200);
-      const notifications: Notification[] = response.body;
+      const notifications: Notification[] = response.body.data;
       expect(notifications).toHaveLength(2); // Only the two unread ones
       expect(notifications.every((n) => !n.is_read)).toBe(true);
     });
@@ -73,7 +73,7 @@ describe('Notification API Routes Integration Tests', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(response.status).toBe(200);
-      const notifications: Notification[] = response.body;
+      const notifications: Notification[] = response.body.data;
       expect(notifications).toHaveLength(3); // All three notifications
     });
 
@@ -84,7 +84,7 @@ describe('Notification API Routes Integration Tests', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(response1.status).toBe(200);
-      const notifications1: Notification[] = response1.body;
+      const notifications1: Notification[] = response1.body.data;
       expect(notifications1).toHaveLength(1);
       expect(notifications1[0].content).toBe('Your second unread notification'); // Assuming DESC order
 
@@ -94,7 +94,7 @@ describe('Notification API Routes Integration Tests', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(response2.status).toBe(200);
-      const notifications2: Notification[] = response2.body;
+      const notifications2: Notification[] = response2.body.data;
       expect(notifications2).toHaveLength(1);
       expect(notifications2[0].content).toBe('Your first unread notification');
     });
@@ -145,4 +145,4 @@ describe('Notification API Routes Integration Tests', () => {
       expect(Number(finalUnreadCountRes.rows[0].count)).toBe(0);
     });
   });
-});
\ No newline at end of file
+});
diff --git a/src/tests/integration/price.integration.test.ts b/src/tests/integration/price.integration.test.ts
index 404f8c82..f6c3050d 100644
--- a/src/tests/integration/price.integration.test.ts
+++ b/src/tests/integration/price.integration.test.ts
@@ -114,17 +114,27 @@ describe('Price History API Integration Test (/api/price-history)', () => {
   });
 
   it('should return the correct price history for a given master item ID', async () => {
-    const response = await request.post('/api/price-history')
+    const response = await request
+      .post('/api/price-history')
       .set('Authorization', `Bearer ${authToken}`)
       .send({ masterItemIds: [masterItemId] });
 
     expect(response.status).toBe(200);
-    expect(response.body).toBeInstanceOf(Array);
-    expect(response.body).toHaveLength(3);
+    expect(response.body.data).toBeInstanceOf(Array);
+    expect(response.body.data).toHaveLength(3);
 
-    expect(response.body[0]).toMatchObject({ master_item_id: masterItemId, price_in_cents: 199 });
-    expect(response.body[1]).toMatchObject({ master_item_id: masterItemId, price_in_cents: 249 });
-    expect(response.body[2]).toMatchObject({ master_item_id: masterItemId, price_in_cents: 299 });
+    expect(response.body.data[0]).toMatchObject({
+      master_item_id: masterItemId,
+      price_in_cents: 199,
+    });
+    expect(response.body.data[1]).toMatchObject({
+      master_item_id: masterItemId,
+      price_in_cents: 249,
+    });
+    expect(response.body.data[2]).toMatchObject({
+      master_item_id: masterItemId,
+      price_in_cents: 299,
+    });
   });
 
   it('should respect the limit parameter', async () => {
@@ -134,9 +144,9 @@ describe('Price History API Integration Test (/api/price-history)', () => {
       .send({ masterItemIds: [masterItemId], limit: 2 });
 
     expect(response.status).toBe(200);
-    expect(response.body).toHaveLength(2);
-    expect(response.body[0].price_in_cents).toBe(199);
-    expect(response.body[1].price_in_cents).toBe(249);
+    expect(response.body.data).toHaveLength(2);
+    expect(response.body.data[0].price_in_cents).toBe(199);
+    expect(response.body.data[1].price_in_cents).toBe(249);
   });
 
   it('should respect the offset parameter', async () => {
@@ -146,18 +156,19 @@ describe('Price History API Integration Test (/api/price-history)', () => {
       .send({ masterItemIds: [masterItemId], limit: 2, offset: 1 });
 
     expect(response.status).toBe(200);
-    expect(response.body).toHaveLength(2);
-    expect(response.body[0].price_in_cents).toBe(249);
-    expect(response.body[1].price_in_cents).toBe(299);
+    expect(response.body.data).toHaveLength(2);
+    expect(response.body.data[0].price_in_cents).toBe(249);
+    expect(response.body.data[1].price_in_cents).toBe(299);
   });
 
   it('should return price history sorted by date in ascending order', async () => {
-    const response = await request.post('/api/price-history')
+    const response = await request
+      .post('/api/price-history')
       .set('Authorization', `Bearer ${authToken}`)
       .send({ masterItemIds: [masterItemId] });
 
     expect(response.status).toBe(200);
-    const history = response.body;
+    const history = response.body.data;
     expect(history).toHaveLength(3);
 
     const date1 = new Date(history[0].date).getTime();
@@ -169,10 +180,11 @@ describe('Price History API Integration Test (/api/price-history)', () => {
   });
 
   it('should return an empty array for a master item ID with no price history', async () => {
-    const response = await request.post('/api/price-history')
+    const response = await request
+      .post('/api/price-history')
       .set('Authorization', `Bearer ${authToken}`)
       .send({ masterItemIds: [999999] });
     expect(response.status).toBe(200);
-    expect(response.body).toEqual([]);
+    expect(response.body.data).toEqual([]);
   });
-});
\ No newline at end of file
+});
diff --git a/src/tests/integration/public.routes.integration.test.ts b/src/tests/integration/public.routes.integration.test.ts
index d57aa9a9..eaa8a81b 100644
--- a/src/tests/integration/public.routes.integration.test.ts
+++ b/src/tests/integration/public.routes.integration.test.ts
@@ -118,16 +118,16 @@ describe('Public API Routes Integration Tests', () => {
     it('GET /api/health/time should return the server time', async () => {
       const response = await request.get('/api/health/time');
       expect(response.status).toBe(200);
-      expect(response.body).toHaveProperty('currentTime');
-      expect(response.body).toHaveProperty('year');
-      expect(response.body).toHaveProperty('week');
+      expect(response.body.data).toHaveProperty('currentTime');
+      expect(response.body.data).toHaveProperty('year');
+      expect(response.body.data).toHaveProperty('week');
     });
   });
 
   describe('Public Data Endpoints', () => {
     it('GET /api/flyers should return a list of flyers', async () => {
       const response = await request.get('/api/flyers');
-      const flyers: Flyer[] = response.body;
+      const flyers: Flyer[] = response.body.data;
       expect(flyers.length).toBeGreaterThan(0);
       const foundFlyer = flyers.find((f) => f.flyer_id === testFlyer.flyer_id);
       expect(foundFlyer).toBeDefined();
@@ -136,7 +136,7 @@ describe('Public API Routes Integration Tests', () => {
 
     it('GET /api/flyers/:id/items should return items for a specific flyer', async () => {
       const response = await request.get(`/api/flyers/${testFlyer.flyer_id}/items`);
-      const items: FlyerItem[] = response.body;
+      const items: FlyerItem[] = response.body.data;
       expect(response.status).toBe(200);
       expect(items).toBeInstanceOf(Array);
       expect(items.length).toBe(1);
@@ -146,7 +146,7 @@ describe('Public API Routes Integration Tests', () => {
     it('POST /api/flyers/items/batch-fetch should return items for multiple flyers', async () => {
       const flyerIds = [testFlyer.flyer_id];
       const response = await request.post('/api/flyers/items/batch-fetch').send({ flyerIds });
-      const items: FlyerItem[] = response.body;
+      const items: FlyerItem[] = response.body.data;
       expect(response.status).toBe(200);
       expect(items).toBeInstanceOf(Array);
       expect(items.length).toBeGreaterThan(0);
@@ -156,13 +156,13 @@ describe('Public API Routes Integration Tests', () => {
       const flyerIds = [testFlyer.flyer_id];
       const response = await request.post('/api/flyers/items/batch-count').send({ flyerIds });
       expect(response.status).toBe(200);
-      expect(response.body.count).toBeTypeOf('number');
-      expect(response.body.count).toBeGreaterThan(0);
+      expect(response.body.data.count).toBeTypeOf('number');
+      expect(response.body.data.count).toBeGreaterThan(0);
     });
 
     it('GET /api/personalization/master-items should return a list of master grocery items', async () => {
       const response = await request.get('/api/personalization/master-items');
-      const masterItems = response.body;
+      const masterItems = response.body.data;
       expect(response.status).toBe(200);
       expect(masterItems).toBeInstanceOf(Array);
       expect(masterItems.length).toBeGreaterThan(0); // This relies on seed data for master items.
@@ -171,7 +171,7 @@ describe('Public API Routes Integration Tests', () => {
 
     it('GET /api/recipes/by-sale-percentage should return recipes', async () => {
       const response = await request.get('/api/recipes/by-sale-percentage?minPercentage=10');
-      const recipes: Recipe[] = response.body;
+      const recipes: Recipe[] = response.body.data;
       expect(response.status).toBe(200);
       expect(recipes).toBeInstanceOf(Array);
     });
@@ -181,7 +181,7 @@ describe('Public API Routes Integration Tests', () => {
       const response = await request.get(
         '/api/recipes/by-ingredient-and-tag?ingredient=Test&tag=Public',
       );
-      const recipes: Recipe[] = response.body;
+      const recipes: Recipe[] = response.body.data;
       expect(response.status).toBe(200);
       expect(recipes).toBeInstanceOf(Array);
     });
@@ -194,7 +194,7 @@ describe('Public API Routes Integration Tests', () => {
       );
       createdRecipeCommentIds.push(commentRes.rows[0].recipe_comment_id);
       const response = await request.get(`/api/recipes/${testRecipe.recipe_id}/comments`);
-      const comments: RecipeComment[] = response.body;
+      const comments: RecipeComment[] = response.body.data;
       expect(response.status).toBe(200);
       expect(comments).toBeInstanceOf(Array);
       expect(comments.length).toBe(1);
@@ -203,7 +203,7 @@ describe('Public API Routes Integration Tests', () => {
 
     it('GET /api/stats/most-frequent-sales should return frequent items', async () => {
       const response = await request.get('/api/stats/most-frequent-sales?days=365&limit=5');
-      const items = response.body;
+      const items = response.body.data;
       expect(response.status).toBe(200);
       expect(items).toBeInstanceOf(Array);
     });
@@ -211,7 +211,7 @@ describe('Public API Routes Integration Tests', () => {
     it('GET /api/personalization/dietary-restrictions should return a list of restrictions', async () => {
       // This test relies on static seed data for a lookup table, which is acceptable.
       const response = await request.get('/api/personalization/dietary-restrictions');
-      const restrictions: DietaryRestriction[] = response.body;
+      const restrictions: DietaryRestriction[] = response.body.data;
       expect(response.status).toBe(200);
       expect(restrictions).toBeInstanceOf(Array);
       expect(restrictions.length).toBeGreaterThan(0);
@@ -220,7 +220,7 @@ describe('Public API Routes Integration Tests', () => {
 
     it('GET /api/personalization/appliances should return a list of appliances', async () => {
       const response = await request.get('/api/personalization/appliances');
-      const appliances: Appliance[] = response.body;
+      const appliances: Appliance[] = response.body.data;
       expect(response.status).toBe(200);
       expect(appliances).toBeInstanceOf(Array);
       expect(appliances.length).toBeGreaterThan(0);
diff --git a/src/tests/integration/recipe.integration.test.ts b/src/tests/integration/recipe.integration.test.ts
index 7fc25d9a..5b2c3d3a 100644
--- a/src/tests/integration/recipe.integration.test.ts
+++ b/src/tests/integration/recipe.integration.test.ts
@@ -69,9 +69,9 @@ describe('Recipe API Routes Integration Tests', () => {
       const response = await request.get(`/api/recipes/${testRecipe.recipe_id}`);
 
       expect(response.status).toBe(200);
-      expect(response.body).toBeDefined();
-      expect(response.body.recipe_id).toBe(testRecipe.recipe_id);
-      expect(response.body.name).toBe('Integration Test Recipe');
+      expect(response.body.data).toBeDefined();
+      expect(response.body.data.recipe_id).toBe(testRecipe.recipe_id);
+      expect(response.body.data.name).toBe('Integration Test Recipe');
     });
 
     it('should return 404 for a non-existent recipe ID', async () => {
@@ -94,7 +94,7 @@ describe('Recipe API Routes Integration Tests', () => {
 
     // Assert the response from the POST request
     expect(response.status).toBe(201);
-    const createdRecipe: Recipe = response.body;
+    const createdRecipe: Recipe = response.body.data;
     expect(createdRecipe).toBeDefined();
     expect(createdRecipe.recipe_id).toBeTypeOf('number');
     expect(createdRecipe.name).toBe(newRecipeData.name);
@@ -106,7 +106,7 @@ describe('Recipe API Routes Integration Tests', () => {
     // Verify the recipe can be fetched from the public endpoint
     const verifyResponse = await request.get(`/api/recipes/${createdRecipe.recipe_id}`);
     expect(verifyResponse.status).toBe(200);
-    expect(verifyResponse.body.name).toBe(newRecipeData.name);
+    expect(verifyResponse.body.data.name).toBe(newRecipeData.name);
   });
   it('should allow an authenticated user to update their own recipe', async () => {
     const recipeUpdates = {
@@ -121,14 +121,14 @@ describe('Recipe API Routes Integration Tests', () => {
 
     // Assert the response from the PUT request
     expect(response.status).toBe(200);
-    const updatedRecipe: Recipe = response.body;
+    const updatedRecipe: Recipe = response.body.data;
     expect(updatedRecipe.name).toBe(recipeUpdates.name);
     expect(updatedRecipe.instructions).toBe(recipeUpdates.instructions);
 
     // Verify the changes were persisted by fetching the recipe again
     const verifyResponse = await request.get(`/api/recipes/${testRecipe.recipe_id}`);
     expect(verifyResponse.status).toBe(200);
-    expect(verifyResponse.body.name).toBe(recipeUpdates.name);
+    expect(verifyResponse.body.data.name).toBe(recipeUpdates.name);
   });
   it.todo("should prevent a user from updating another user's recipe");
   it.todo('should allow an authenticated user to delete their own recipe');
@@ -148,7 +148,7 @@ describe('Recipe API Routes Integration Tests', () => {
         .send({ ingredients });
 
       expect(response.status).toBe(200);
-      expect(response.body).toEqual({ suggestion: mockSuggestion });
+      expect(response.body.data).toEqual({ suggestion: mockSuggestion });
       expect(aiService.generateRecipeSuggestion).toHaveBeenCalledWith(
         ingredients,
         expect.anything(),
diff --git a/src/tests/integration/server.integration.test.ts b/src/tests/integration/server.integration.test.ts
index 9ca032d4..500be07b 100644
--- a/src/tests/integration/server.integration.test.ts
+++ b/src/tests/integration/server.integration.test.ts
@@ -58,7 +58,7 @@ describe('Server Initialization Smoke Test', () => {
     // by the application user, which is critical for file uploads.
     expect(response.status).toBe(200);
     expect(response.body.success).toBe(true);
-    expect(response.body.message).toContain('is accessible and writable');
+    expect(response.body.data.message).toContain('is accessible and writable');
   });
 
   it('should respond with 200 OK for GET /api/health/redis', async () => {
@@ -70,6 +70,6 @@ describe('Server Initialization Smoke Test', () => {
     // essential for the background job queueing system (BullMQ).
     expect(response.status).toBe(200);
     expect(response.body.success).toBe(true);
-    expect(response.body.message).toBe('Redis connection is healthy.');
+    expect(response.body.data.message).toBe('Redis connection is healthy.');
   });
 });
diff --git a/src/tests/integration/user.integration.test.ts b/src/tests/integration/user.integration.test.ts
index dbe410b7..65ba61a2 100644
--- a/src/tests/integration/user.integration.test.ts
+++ b/src/tests/integration/user.integration.test.ts
@@ -67,7 +67,7 @@ describe('User API Routes Integration Tests', () => {
     const response = await request
       .get('/api/users/profile')
       .set('Authorization', `Bearer ${authToken}`);
-    const profile = response.body;
+    const profile = response.body.data;
 
     // Assert: Verify the profile data matches the created user.
     expect(response.status).toBe(200);
@@ -88,7 +88,7 @@ describe('User API Routes Integration Tests', () => {
       .put('/api/users/profile')
       .set('Authorization', `Bearer ${authToken}`)
       .send(profileUpdates);
-    const updatedProfile = response.body;
+    const updatedProfile = response.body.data;
 
     // Assert: Check that the returned profile reflects the changes.
     expect(response.status).toBe(200);
@@ -98,7 +98,7 @@ describe('User API Routes Integration Tests', () => {
     const refetchResponse = await request
       .get('/api/users/profile')
       .set('Authorization', `Bearer ${authToken}`);
-    const refetchedProfile = refetchResponse.body;
+    const refetchedProfile = refetchResponse.body.data;
     expect(refetchedProfile.full_name).toBe('Updated Test User');
   });
 
@@ -114,7 +114,7 @@ describe('User API Routes Integration Tests', () => {
       .put('/api/users/profile')
       .set('Authorization', `Bearer ${authToken}`)
       .send(profileUpdates);
-    const updatedProfile = response.body;
+    const updatedProfile = response.body.data;
 
     // Assert: Check that the returned profile reflects the changes.
     expect(response.status).toBe(200);
@@ -125,7 +125,7 @@ describe('User API Routes Integration Tests', () => {
     const refetchResponse = await request
       .get('/api/users/profile')
       .set('Authorization', `Bearer ${authToken}`);
-    expect(refetchResponse.body.avatar_url).toBeNull();
+    expect(refetchResponse.body.data.avatar_url).toBeNull();
   });
 
   it('should update user preferences via PUT /api/users/profile/preferences', async () => {
@@ -139,7 +139,7 @@ describe('User API Routes Integration Tests', () => {
       .put('/api/users/profile/preferences')
       .set('Authorization', `Bearer ${authToken}`)
       .send(preferenceUpdates);
-    const updatedProfile = response.body;
+    const updatedProfile = response.body.data;
 
     // Assert: Check that the preferences object in the returned profile is updated.
     expect(response.status).toBe(200);
@@ -160,10 +160,10 @@ describe('User API Routes Integration Tests', () => {
     });
 
     expect(response.status).toBe(400);
-    const errorData = response.body as { message: string; errors: { message: string }[] };
-    // For validation errors, the detailed messages are in the `errors` array.
+    const errorData = response.body.error as { message: string; details: { message: string }[] };
+    // For validation errors, the detailed messages are in the `details` array.
     // We join them to check for the specific feedback from the password strength checker.
-    const detailedErrorMessage = errorData.errors?.map((e) => e.message).join(' ');
+    const detailedErrorMessage = errorData.details?.map((e) => e.message).join(' ');
     expect(detailedErrorMessage).toMatch(/Password is too weak/);
   });
 
@@ -185,14 +185,14 @@ describe('User API Routes Integration Tests', () => {
 
     // Assert: Check for a successful deletion message.
     expect(response.status).toBe(200);
-    expect(deleteResponse.message).toBe('Account deleted successfully.');
+    expect(deleteResponse.data.message).toBe('Account deleted successfully.');
 
     // Assert (Verification): Attempting to log in again with the same credentials should now fail.
     const loginResponse = await request
       .post('/api/auth/login')
       .send({ email: deletionEmail, password: TEST_PASSWORD });
     expect(loginResponse.status).toBe(401);
-    const errorData = loginResponse.body;
+    const errorData = loginResponse.body.error;
     expect(errorData.message).toBe('Incorrect email or password.');
   });
 
@@ -210,7 +210,7 @@ describe('User API Routes Integration Tests', () => {
       const errorData = resetRequestRawResponse.body;
       throw new Error(errorData.message || 'Password reset request failed');
     }
-    const resetRequestResponse = resetRequestRawResponse.body;
+    const resetRequestResponse = resetRequestRawResponse.body.data;
     const resetToken = resetRequestResponse.token;
 
     // Assert 1: Check that we received a token.
@@ -226,7 +226,7 @@ describe('User API Routes Integration Tests', () => {
       const errorData = resetRawResponse.body;
       throw new Error(errorData.message || 'Password reset failed');
     }
-    const resetResponse = resetRawResponse.body;
+    const resetResponse = resetRawResponse.body.data;
 
     // Assert 2: Check for a successful password reset message.
     expect(resetResponse.message).toBe('Password has been reset successfully.');
@@ -235,7 +235,7 @@ describe('User API Routes Integration Tests', () => {
     const loginResponse = await request
       .post('/api/auth/login')
       .send({ email: resetEmail, password: newPassword });
-    const loginData = loginResponse.body;
+    const loginData = loginResponse.body.data;
     expect(loginData.userprofile).toBeDefined();
     expect(loginData.userprofile.user.user_id).toBe(resetUser.user.user_id);
   });
@@ -247,7 +247,7 @@ describe('User API Routes Integration Tests', () => {
         .post('/api/users/watched-items')
         .set('Authorization', `Bearer ${authToken}`)
         .send({ itemName: 'Integration Test Item', category: 'Other/Miscellaneous' });
-      const newItem = addResponse.body;
+      const newItem = addResponse.body.data;
 
       if (newItem?.master_grocery_item_id)
         createdMasterItemIds.push(newItem.master_grocery_item_id);
@@ -259,7 +259,7 @@ describe('User API Routes Integration Tests', () => {
       const watchedItemsResponse = await request
         .get('/api/users/watched-items')
         .set('Authorization', `Bearer ${authToken}`);
-      const watchedItems = watchedItemsResponse.body;
+      const watchedItems = watchedItemsResponse.body.data;
 
       // Assert 2: Verify the new item is in the user's watched list.
       expect(
@@ -279,7 +279,7 @@ describe('User API Routes Integration Tests', () => {
       const finalWatchedItemsResponse = await request
         .get('/api/users/watched-items')
         .set('Authorization', `Bearer ${authToken}`);
-      const finalWatchedItems = finalWatchedItemsResponse.body;
+      const finalWatchedItems = finalWatchedItemsResponse.body.data;
       expect(
         finalWatchedItems.some(
           (item: MasterGroceryItem) =>
@@ -294,7 +294,7 @@ describe('User API Routes Integration Tests', () => {
         .post('/api/users/shopping-lists')
         .set('Authorization', `Bearer ${authToken}`)
         .send({ name: 'My Integration Test List' });
-      const newList = createListResponse.body;
+      const newList = createListResponse.body.data;
 
       // Assert 1: Check that the list was created.
       expect(createListResponse.status).toBe(201);
@@ -305,7 +305,7 @@ describe('User API Routes Integration Tests', () => {
         .post(`/api/users/shopping-lists/${newList.shopping_list_id}/items`)
         .set('Authorization', `Bearer ${authToken}`)
         .send({ customItemName: 'Custom Test Item' });
-      const addedItem = addItemResponse.body;
+      const addedItem = addItemResponse.body.data;
 
       // Assert 2: Check that the item was added.
       expect(addItemResponse.status).toBe(201);
@@ -315,7 +315,7 @@ describe('User API Routes Integration Tests', () => {
       const fetchResponse = await request
         .get('/api/users/shopping-lists')
         .set('Authorization', `Bearer ${authToken}`);
-      const lists = fetchResponse.body;
+      const lists = fetchResponse.body.data;
       expect(fetchResponse.status).toBe(200);
       const updatedList = lists.find(
         (l: ShoppingList) => l.shopping_list_id === newList.shopping_list_id,
@@ -340,7 +340,7 @@ describe('User API Routes Integration Tests', () => {
 
     // Assert: Check the response
     expect(response.status).toBe(200);
-    const updatedProfile = response.body;
+    const updatedProfile = response.body.data;
     expect(updatedProfile.avatar_url).toBeDefined();
     expect(updatedProfile.avatar_url).not.toBeNull();
     expect(updatedProfile.avatar_url).toContain('/uploads/avatars/test-avatar');
@@ -349,7 +349,7 @@ describe('User API Routes Integration Tests', () => {
     const verifyResponse = await request
       .get('/api/users/profile')
       .set('Authorization', `Bearer ${authToken}`);
-    const refetchedProfile = verifyResponse.body;
+    const refetchedProfile = verifyResponse.body.data;
     expect(refetchedProfile.avatar_url).toBe(updatedProfile.avatar_url);
   });
 
@@ -365,9 +365,9 @@ describe('User API Routes Integration Tests', () => {
       .attach('avatar', invalidFileBuffer, invalidFileName);
 
     // Assert: Check for a 400 Bad Request response.
-    // This error comes from the multer fileFilter configuration in the route.
+    // This error comes from ValidationError via the global errorHandler (sendError format).
     expect(response.status).toBe(400);
-    expect(response.body.message).toBe('Only image files are allowed!');
+    expect(response.body.error.message).toBe('Only image files are allowed!');
   });
 
   it('should reject avatar upload for a file that is too large', async () => {
diff --git a/src/tests/integration/user.routes.integration.test.ts b/src/tests/integration/user.routes.integration.test.ts
index 625f81ed..0e61641b 100644
--- a/src/tests/integration/user.routes.integration.test.ts
+++ b/src/tests/integration/user.routes.integration.test.ts
@@ -43,9 +43,9 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(response.status).toBe(200);
-      expect(response.body).toBeDefined();
-      expect(response.body.user.email).toBe(testUser.user.email);
-      expect(response.body.role).toBe('user');
+      expect(response.body.data).toBeDefined();
+      expect(response.body.data.user.email).toBe(testUser.user.email);
+      expect(response.body.data.role).toBe('user');
     });
 
     it('should return 401 Unauthorized if no token is provided', async () => {
@@ -63,14 +63,14 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .send({ full_name: newName });
 
       expect(response.status).toBe(200);
-      expect(response.body.full_name).toBe(newName);
+      expect(response.body.data.full_name).toBe(newName);
 
       // Verify the change by fetching the profile again
       const verifyResponse = await request
         .get('/api/users/profile')
         .set('Authorization', `Bearer ${authToken}`);
 
-      expect(verifyResponse.body.full_name).toBe(newName);
+      expect(verifyResponse.body.data.full_name).toBe(newName);
     });
   });
 
@@ -83,15 +83,15 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .send(preferences);
 
       expect(response.status).toBe(200);
-      expect(response.body.preferences).toEqual(preferences);
+      expect(response.body.data.preferences).toEqual(preferences);
 
       // Verify the change by fetching the profile again
       const verifyResponse = await request
         .get('/api/users/profile')
         .set('Authorization', `Bearer ${authToken}`);
 
-      expect(verifyResponse.body.preferences?.darkMode).toBe(true);
-      expect(verifyResponse.body.preferences?.unitSystem).toBe('metric');
+      expect(verifyResponse.body.data.preferences?.darkMode).toBe(true);
+      expect(verifyResponse.body.data.preferences?.unitSystem).toBe('metric');
     });
   });
 
@@ -105,8 +105,8 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .send({ name: listName });
 
       expect(createResponse.status).toBe(201);
-      expect(createResponse.body.name).toBe(listName);
-      const listId = createResponse.body.shopping_list_id;
+      expect(createResponse.body.data.name).toBe(listName);
+      const listId = createResponse.body.data.shopping_list_id;
       expect(listId).toBeDefined();
 
       // 2. Retrieve
@@ -115,7 +115,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .set('Authorization', `Bearer ${authToken}`);
 
       expect(getResponse.status).toBe(200);
-      const foundList = getResponse.body.find(
+      const foundList = getResponse.body.data.find(
         (l: { shopping_list_id: number }) => l.shopping_list_id === listId,
       );
       expect(foundList).toBeDefined();
@@ -130,7 +130,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
       const verifyResponse = await request
         .get('/api/users/shopping-lists')
         .set('Authorization', `Bearer ${authToken}`);
-      const notFoundList = verifyResponse.body.find(
+      const notFoundList = verifyResponse.body.data.find(
         (l: { shopping_list_id: number }) => l.shopping_list_id === listId,
       );
       expect(notFoundList).toBeUndefined();
@@ -144,7 +144,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .set('Authorization', `Bearer ${authToken}`) // Use owner's token
         .send({ name: listName });
       expect(createListResponse.status).toBe(201);
-      const listId = createListResponse.body.shopping_list_id;
+      const listId = createListResponse.body.data.shopping_list_id;
 
       // Arrange: Create a second, "malicious" user.
       const maliciousEmail = `malicious-user-${Date.now()}@example.com`;
@@ -163,7 +163,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
 
       // Assert 1: The request should fail. A 404 is expected because the list is not found for this user.
       expect(addItemResponse.status).toBe(404);
-      expect(addItemResponse.body.message).toContain('Shopping list not found');
+      expect(addItemResponse.body.error.message).toContain('Shopping list not found');
 
       // Act 2: Malicious user attempts to delete the owner's list.
       const deleteResponse = await request
@@ -172,7 +172,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
 
       // Assert 2: This should also fail with a 404.
       expect(deleteResponse.status).toBe(404);
-      expect(deleteResponse.body.message).toContain('Shopping list not found');
+      expect(deleteResponse.body.error.message).toContain('Shopping list not found');
 
       // Act 3: Malicious user attempts to update an item on the owner's list.
       // First, the owner adds an item.
@@ -181,7 +181,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .set('Authorization', `Bearer ${authToken}`) // Owner's token
         .send({ customItemName: 'Legitimate Item' });
       expect(ownerAddItemResponse.status).toBe(201);
-      const itemId = ownerAddItemResponse.body.shopping_list_item_id;
+      const itemId = ownerAddItemResponse.body.data.shopping_list_item_id;
 
       // Now, the malicious user tries to update it.
       const updateItemResponse = await request
@@ -191,7 +191,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
 
       // Assert 3: This should also fail with a 404.
       expect(updateItemResponse.status).toBe(404);
-      expect(updateItemResponse.body.message).toContain('Shopping list item not found');
+      expect(updateItemResponse.body.error.message).toContain('Shopping list item not found');
 
       // Cleanup the list created in this test
       await request
@@ -210,7 +210,7 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .post('/api/users/shopping-lists')
         .set('Authorization', `Bearer ${authToken}`)
         .send({ name: 'Item Test List' });
-      listId = response.body.shopping_list_id;
+      listId = response.body.data.shopping_list_id;
     });
 
     // Clean up the list after the item tests are done
@@ -229,9 +229,9 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .send({ customItemName: 'Test Item' });
 
       expect(response.status).toBe(201);
-      expect(response.body.custom_item_name).toBe('Test Item');
-      expect(response.body.shopping_list_item_id).toBeDefined();
-      itemId = response.body.shopping_list_item_id; // Save for next tests
+      expect(response.body.data.custom_item_name).toBe('Test Item');
+      expect(response.body.data.shopping_list_item_id).toBeDefined();
+      itemId = response.body.data.shopping_list_item_id; // Save for next tests
     });
 
     it('should update an item in a shopping list', async () => {
@@ -242,8 +242,8 @@ describe('User Routes Integration Tests (/api/users)', () => {
         .send(updates);
 
       expect(response.status).toBe(200);
-      expect(response.body.is_purchased).toBe(true);
-      expect(response.body.quantity).toBe(5);
+      expect(response.body.data.is_purchased).toBe(true);
+      expect(response.body.data.quantity).toBe(5);
     });
 
     it('should delete an item from a shopping list', async () => {
diff --git a/src/tests/setup/integration-global-setup.ts b/src/tests/setup/integration-global-setup.ts
index ee784173..c922fa67 100644
--- a/src/tests/setup/integration-global-setup.ts
+++ b/src/tests/setup/integration-global-setup.ts
@@ -2,14 +2,24 @@
 import { execSync } from 'child_process';
 import fs from 'node:fs/promises';
 import path from 'path';
+import os from 'os';
 import type { Server } from 'http';
 import { logger } from '../../services/logger.server';
 import { getPool } from '../../services/db/connection.db';
 
+// --- DEBUG: Log when this file is first loaded/parsed ---
+const SETUP_LOAD_TIME = new Date().toISOString();
+console.error(`\n[GLOBAL-SETUP-DEBUG] Module loaded at ${SETUP_LOAD_TIME}`);
+console.error(`[GLOBAL-SETUP-DEBUG] Current working directory: ${process.cwd()}`);
+console.error(`[GLOBAL-SETUP-DEBUG] NODE_ENV: ${process.env.NODE_ENV}`);
+console.error(`[GLOBAL-SETUP-DEBUG] __filename: ${import.meta.url}`);
+
 // --- Centralized State for Integration Test Lifecycle ---
 let server: Server;
 // This will hold the single database pool instance for the entire test run.
 let globalPool: ReturnType<typeof getPool> | null = null;
+// Temporary directory for test file storage (to avoid modifying committed fixtures)
+let tempStorageDir: string | null = null;
 
 /**
  * Cleans all BullMQ queues to ensure no stale jobs from previous test runs.
@@ -68,26 +78,28 @@ async function cleanAllQueues() {
 }
 
 export async function setup() {
+  console.error(`\n[GLOBAL-SETUP-DEBUG] ========================================`);
+  console.error(`[GLOBAL-SETUP-DEBUG] setup() function STARTED at ${new Date().toISOString()}`);
+  console.error(`[GLOBAL-SETUP-DEBUG] ========================================`);
+
   // Ensure we are in the correct environment for these tests.
   process.env.NODE_ENV = 'test';
   // Fix: Set the FRONTEND_URL globally for the test server instance
   process.env.FRONTEND_URL = 'https://example.com';
 
+  // CRITICAL: Create a temporary directory for test file storage.
+  // This prevents tests from modifying or deleting committed fixture files.
+  // The temp directory is cleaned up in teardown().
+  tempStorageDir = await fs.mkdtemp(path.join(os.tmpdir(), 'flyer-crawler-test-'));
+  const tempFlyerImagesDir = path.join(tempStorageDir, 'flyer-images');
+  await fs.mkdir(path.join(tempFlyerImagesDir, 'icons'), { recursive: true });
+  console.error(`[SETUP] Created temporary storage directory: ${tempFlyerImagesDir}`);
+
   // CRITICAL: Set STORAGE_PATH before importing the server.
   // The multer middleware runs an IIFE on import that creates directories based on this path.
-  // If not set, it defaults to /var/www/.../flyer-images which won't exist in the test environment.
-  if (!process.env.STORAGE_PATH) {
-    // Use path relative to the project root (where tests run from)
-    process.env.STORAGE_PATH = path.resolve(process.cwd(), 'flyer-images');
-  }
-
-  // Ensure the storage directories exist before the server starts
-  try {
-    await fs.mkdir(path.join(process.env.STORAGE_PATH, 'icons'), { recursive: true });
-    console.error(`[SETUP] Created storage directory: ${process.env.STORAGE_PATH}`);
-  } catch (error) {
-    console.error(`[SETUP] Warning: Could not create storage directory: ${error}`);
-  }
+  // Using a temp directory ensures test file operations don't affect committed files.
+  process.env.STORAGE_PATH = tempFlyerImagesDir;
+  console.error(`[SETUP] Set STORAGE_PATH to temporary directory: ${process.env.STORAGE_PATH}`);
 
   console.error(`\n--- [PID:${process.pid}] Running Integration Test GLOBAL Setup ---`);
   console.error(`[SETUP] STORAGE_PATH: ${process.env.STORAGE_PATH}`);
@@ -117,16 +129,37 @@ export async function setup() {
   globalPool = getPool();
 
   // Fix: Dynamic import AFTER env vars are set
+  console.error(`[GLOBAL-SETUP-DEBUG] About to import server module...`);
   const appModule = await import('../../../server');
+  console.error(`[GLOBAL-SETUP-DEBUG] Server module imported successfully`);
   const app = appModule.default;
+  console.error(`[GLOBAL-SETUP-DEBUG] App object type: ${typeof app}`);
 
   // Programmatically start the server within the same process.
   const port = process.env.PORT || 3001;
-  await new Promise<void>((resolve) => {
-    server = app.listen(port, () => {
-      console.log(`✅ In-process test server started on port ${port}`);
-      resolve();
-    });
+  console.error(`[GLOBAL-SETUP-DEBUG] Attempting to start server on port ${port}...`);
+
+  await new Promise<void>((resolve, reject) => {
+    try {
+      server = app.listen(port, () => {
+        console.log(`✅ In-process test server started on port ${port}`);
+        console.error(
+          `[GLOBAL-SETUP-DEBUG] Server listen callback invoked at ${new Date().toISOString()}`,
+        );
+        resolve();
+      });
+
+      server.on('error', (err: NodeJS.ErrnoException) => {
+        console.error(`[GLOBAL-SETUP-DEBUG] Server error event:`, err.message);
+        if (err.code === 'EADDRINUSE') {
+          console.error(`[GLOBAL-SETUP-DEBUG] Port ${port} is already in use!`);
+        }
+        reject(err);
+      });
+    } catch (err) {
+      console.error(`[GLOBAL-SETUP-DEBUG] Error during app.listen:`, err);
+      reject(err);
+    }
   });
 
   /**
@@ -135,23 +168,41 @@ export async function setup() {
    */
   const pingTestBackend = async (): Promise<boolean> => {
     const apiUrl = process.env.VITE_API_BASE_URL || 'http://localhost:3001/api';
+    const pingUrl = `${apiUrl.replace('/api', '')}/api/health/ping`;
+    console.error(`[GLOBAL-SETUP-DEBUG] Pinging: ${pingUrl}`);
     try {
-      const response = await fetch(`${apiUrl.replace('/api', '')}/api/health/ping`);
-      if (!response.ok) return false;
+      const response = await fetch(pingUrl);
+      console.error(`[GLOBAL-SETUP-DEBUG] Ping response status: ${response.status}`);
+      if (!response.ok) {
+        console.error(`[GLOBAL-SETUP-DEBUG] Ping response not OK: ${response.statusText}`);
+        return false;
+      }
       // The ping endpoint returns JSON: { status: 'success', data: { message: 'pong' } }
       const json = await response.json();
+      console.error(`[GLOBAL-SETUP-DEBUG] Ping response JSON:`, JSON.stringify(json));
       return json?.data?.message === 'pong';
     } catch (e) {
+      const errMsg = e instanceof Error ? e.message : String(e);
+      console.error(`[GLOBAL-SETUP-DEBUG] Ping exception: ${errMsg}`);
       logger.debug({ error: e }, 'Ping failed while waiting for server, this is expected.');
       return false;
     }
   };
 
+  console.error(
+    `[GLOBAL-SETUP-DEBUG] Server started, beginning ping loop at ${new Date().toISOString()}`,
+  );
+  console.error(`[GLOBAL-SETUP-DEBUG] Server address info:`, server.address());
+
   const maxRetries = 15;
   const retryDelay = 1000;
   for (let i = 0; i < maxRetries; i++) {
+    console.error(`[GLOBAL-SETUP-DEBUG] Ping attempt ${i + 1}/${maxRetries}`);
     if (await pingTestBackend()) {
       console.log('✅ Backend server is running and responsive.');
+      console.error(
+        `[GLOBAL-SETUP-DEBUG] setup() function COMPLETED SUCCESSFULLY at ${new Date().toISOString()}`,
+      );
       return;
     }
     console.log(
@@ -160,6 +211,10 @@ export async function setup() {
     await new Promise((resolve) => setTimeout(resolve, retryDelay));
   }
 
+  console.error(`[GLOBAL-SETUP-DEBUG] All ${maxRetries} ping attempts failed!`);
+  console.error(`[GLOBAL-SETUP-DEBUG] Server listening status: ${server.listening}`);
+  console.error(`[GLOBAL-SETUP-DEBUG] Server address: ${JSON.stringify(server.address())}`);
+
   throw new Error('Backend server failed to start.');
 }
 
@@ -175,4 +230,13 @@ export async function teardown() {
     await globalPool.end();
     console.log('✅ Global database pool teardown complete.');
   }
+  // 3. Clean up the temporary storage directory.
+  if (tempStorageDir) {
+    try {
+      await fs.rm(tempStorageDir, { recursive: true, force: true });
+      console.log(`✅ Cleaned up temporary storage directory: ${tempStorageDir}`);
+    } catch (error) {
+      console.error(`⚠️ Warning: Could not clean up temp directory ${tempStorageDir}:`, error);
+    }
+  }
 }
diff --git a/vitest.config.integration.ts b/vitest.config.integration.ts
index 3134f6e3..37963358 100644
--- a/vitest.config.integration.ts
+++ b/vitest.config.integration.ts
@@ -2,6 +2,8 @@
 import { defineConfig, mergeConfig } from 'vitest/config';
 import type { UserConfig } from 'vite';
 import viteConfig from './vite.config';
+import * as fs from 'fs';
+import * as path from 'path';
 
 // Ensure NODE_ENV is set to 'test' for all Vitest runs.
 process.env.NODE_ENV = 'test';
@@ -9,7 +11,21 @@ process.env.NODE_ENV = 'test';
 // 1. Separate the 'test' config (which has Unit Test settings)
 //    from the rest of the general Vite config (plugins, aliases, etc.)
 // DEBUG: Use console.error to ensure logs appear in CI/CD output
-console.error('[DEBUG] Loading vitest.config.integration.ts...');
+console.error(`[DEBUG] Loading vitest.config.integration.ts at ${new Date().toISOString()}...`);
+console.error(`[DEBUG] CWD: ${process.cwd()}`);
+
+// Check if the integration test directory exists and list its contents
+const integrationTestDir = path.resolve(process.cwd(), 'src/tests/integration');
+try {
+  const files = fs.readdirSync(integrationTestDir);
+  console.error(
+    `[DEBUG] Integration test directory (${integrationTestDir}) contains ${files.length} files:`,
+  );
+  files.forEach((f) => console.error(`[DEBUG]   - ${f}`));
+} catch (e) {
+  console.error(`[DEBUG] ERROR: Could not read integration test directory: ${integrationTestDir}`);
+  console.error(`[DEBUG] Error: ${e instanceof Error ? e.message : String(e)}`);
+}
 
 // Define a type that includes the 'test' property from Vitest's config.
 // This allows us to destructure it in a type-safe way without using 'as any'.