diff --git a/src/features/flyer/FlyerUploader.test.tsx b/src/features/flyer/FlyerUploader.test.tsx
index c3ab5c14..61ef1bfe 100644
--- a/src/features/flyer/FlyerUploader.test.tsx
+++ b/src/features/flyer/FlyerUploader.test.tsx
@@ -328,10 +328,11 @@ describe('FlyerUploader', () => {
 
   it('should handle a duplicate flyer error (409)', async () => {
     console.log('--- [TEST LOG] ---: 1. Setting up mock for 409 duplicate error.');
-    // The API client now throws a structured error for non-2xx responses.
+    // The API client throws a structured error, which useFlyerUploader now parses
+    // to set both the errorMessage and the duplicateFlyerId.
     mockedAiApiClient.uploadAndProcessFlyer.mockRejectedValue({
       status: 409,
-      body: { flyerId: 99, message: 'Duplicate' },
+      body: { flyerId: 99, message: 'This flyer has already been processed.' },
   });
 
     console.log('--- [TEST LOG] ---: 2. Rendering and uploading.');
@@ -345,9 +346,10 @@ describe('FlyerUploader', () => {
 
     try {
       console.log('--- [TEST LOG] ---: 4. AWAITING duplicate flyer message...');
-      expect(
-        await screen.findByText(/This flyer has already been processed/i),
-      ).toBeInTheDocument();
+      // With the fix, the duplicate error message and the link are combined into a single paragraph.
+      // We now look for this combined message.
+      const errorMessage = await screen.findByText(/This flyer has already been processed. You can view it here:/i);
+      expect(errorMessage).toBeInTheDocument();
       console.log('--- [TEST LOG] ---: 5. SUCCESS: Duplicate message found.');
     } catch (error) {
       console.error('--- [TEST LOG] ---: 5. ERROR: findByText for duplicate message timed out.');
diff --git a/src/features/flyer/FlyerUploader.tsx b/src/features/flyer/FlyerUploader.tsx
index 3983ff81..75277128 100644
--- a/src/features/flyer/FlyerUploader.tsx
+++ b/src/features/flyer/FlyerUploader.tsx
@@ -30,6 +30,12 @@ export const FlyerUploader: React.FC<FlyerUploaderProps> = ({ onProcessingComple
     if (statusMessage) logger.info(`FlyerUploader Status: ${statusMessage}`);
   }, [statusMessage]);
 
+  useEffect(() => {
+    if (errorMessage) {
+      logger.error(`[FlyerUploader] Error encountered: ${errorMessage}`, { duplicateFlyerId });
+    }
+  }, [errorMessage, duplicateFlyerId]);
+
   // Handle completion and navigation
   useEffect(() => {
     if (processingState === 'completed' && flyerId) {
@@ -94,14 +100,15 @@ export const FlyerUploader: React.FC<FlyerUploaderProps> = ({ onProcessingComple
 
           {errorMessage && (
             <div className="text-red-600 dark:text-red-400 font-semibold p-4 bg-red-100 dark:bg-red-900/30 rounded-md">
-              <p>{errorMessage}</p>
-              {duplicateFlyerId && (
+              {duplicateFlyerId ? (
                 <p>
-                  This flyer has already been processed. You can view it here:{' '}
+                  {errorMessage} You can view it here:{' '}
                   <Link to={`/flyers/${duplicateFlyerId}`} className="text-blue-500 underline" data-discover="true">
                     Flyer #{duplicateFlyerId}
                   </Link>
                 </p>
+              ) : (
+                <p>{errorMessage}</p>
               )}
             </div>
           )}
diff --git a/src/hooks/useApi.ts b/src/hooks/useApi.ts
index 28057e63..0b79015d 100644
--- a/src/hooks/useApi.ts
+++ b/src/hooks/useApi.ts
@@ -29,6 +29,14 @@ export function useApi<T, TArgs extends unknown[]>(
   const lastErrorMessageRef = useRef<string | null>(null);
   const abortControllerRef = useRef<AbortController>(new AbortController());
 
+  // Use a ref to track the latest apiFunction. This allows us to keep `execute` stable
+  // even if `apiFunction` is recreated on every render (common with inline arrow functions).
+  const apiFunctionRef = useRef(apiFunction);
+
+  useEffect(() => {
+    apiFunctionRef.current = apiFunction;
+  }, [apiFunction]);
+
   // This effect ensures that when the component using the hook unmounts,
   // any in-flight request is cancelled.
   useEffect(() => {
@@ -59,7 +67,7 @@ export function useApi<T, TArgs extends unknown[]>(
       }
 
       try {
-        const response = await apiFunction(...args, abortControllerRef.current.signal);
+        const response = await apiFunctionRef.current(...args, abortControllerRef.current.signal);
 
         if (!response.ok) {
           // Attempt to parse a JSON error response. This is aligned with ADR-003,
@@ -98,7 +106,17 @@ export function useApi<T, TArgs extends unknown[]>(
         }
         return result;
       } catch (e) {
-        const err = e instanceof Error ? e : new Error('An unknown error occurred.');
+        let err: Error;
+        if (e instanceof Error) {
+          err = e;
+        } else if (typeof e === 'object' && e !== null && 'status' in e) {
+          // Handle structured errors (e.g. { status: 409, body: { ... } })
+          const structuredError = e as { status: number; body?: { message?: string } };
+          const message = structuredError.body?.message || `Request failed with status ${structuredError.status}`;
+          err = new Error(message);
+        } else {
+          err = new Error('An unknown error occurred.');
+        }
         // If the error is an AbortError, it's an intentional cancellation, so we don't set an error state.
         if (err.name === 'AbortError') {
           logger.info('API request was cancelled.', { functionName: apiFunction.name });
@@ -122,7 +140,7 @@ export function useApi<T, TArgs extends unknown[]>(
         setIsRefetching(false);
       }
     },
-    [apiFunction],
+    [], // execute is now stable because it uses apiFunctionRef
   ); // abortControllerRef is stable
 
   return { execute, loading, isRefetching, error, data, reset };
diff --git a/src/hooks/useFlyerUploader.ts b/src/hooks/useFlyerUploader.ts
index 8d02ac60..065a29e7 100644
--- a/src/hooks/useFlyerUploader.ts
+++ b/src/hooks/useFlyerUploader.ts
@@ -1,6 +1,6 @@
 // src/hooks/useFlyerUploader.ts
 // src/hooks/useFlyerUploader.ts
-import { useState, useCallback } from 'react';
+import { useState, useCallback, useMemo } from 'react';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import {
   uploadAndProcessFlyer,
@@ -14,6 +14,28 @@ import type { ProcessingStage } from '../types';
 
 export type ProcessingState = 'idle' | 'uploading' | 'polling' | 'completed' | 'error';
 
+// Define a type for the structured error thrown by the API client
+interface ApiError {
+  status: number;
+  body: {
+    message: string;
+    flyerId?: number;
+  };
+}
+
+// Type guard to check if an error is a structured API error
+function isApiError(error: unknown): error is ApiError {
+  return (
+    typeof error === 'object' &&
+    error !== null &&
+    'status' in error &&
+    typeof (error as { status: unknown }).status === 'number' &&
+    'body' in error &&
+    typeof (error as { body: unknown }).body === 'object' &&
+    (error as { body: unknown }).body !== null &&
+    'message' in ((error as { body: unknown }).body as object)
+  );
+}
 export const useFlyerUploader = () => {
   const queryClient = useQueryClient();
   const [jobId, setJobId] = useState<string | null>(null);
@@ -81,40 +103,55 @@ export const useFlyerUploader = () => {
     queryClient.removeQueries({ queryKey: ['jobStatus'] });
   }, [uploadMutation, queryClient]);
 
-  // Consolidate state for the UI from the react-query hooks
-  const processingState = ((): ProcessingState => {
-    if (uploadMutation.isPending) return 'uploading';
-    if (jobStatus && (jobStatus.state === 'active' || jobStatus.state === 'waiting'))
-      return 'polling';
-    if (jobStatus?.state === 'completed') {
-      // If the job is complete but didn't return a flyerId, it's an error state.
-      if (!jobStatus.returnValue?.flyerId) {
-        return 'error';
+  // Consolidate state derivation for the UI from the react-query hooks using useMemo.
+  // This improves performance by memoizing the derived state and makes the logic easier to follow.
+  const { processingState, errorMessage, duplicateFlyerId, flyerId, statusMessage } = useMemo(() => {
+    const state: ProcessingState = (() => {
+      if (uploadMutation.isPending) return 'uploading';
+      if (jobStatus && (jobStatus.state === 'active' || jobStatus.state === 'waiting'))
+        return 'polling';
+      if (jobStatus?.state === 'completed') {
+        if (!jobStatus.returnValue?.flyerId) return 'error';
+        return 'completed';
       }
-      return 'completed';
-    }
-    if (uploadMutation.isError || jobStatus?.state === 'failed' || pollError) return 'error';
-    return 'idle';
-  })();
+      if (uploadMutation.isError || jobStatus?.state === 'failed' || pollError) return 'error';
+      return 'idle';
+    })();
 
-  const getErrorMessage = () => {
-    const uploadError = uploadMutation.error as any;
-    if (uploadMutation.isError) {
-      return uploadError?.body?.message || uploadError?.message || 'Upload failed.';
-    }
-    if (pollError) return `Polling failed: ${pollError.message}`;
-    if (jobStatus?.state === 'failed') {
-      return `Processing failed: ${jobStatus.progress?.message || jobStatus.failedReason}`;
-    }
-    if (jobStatus?.state === 'completed' && !jobStatus.returnValue?.flyerId) {
-      return 'Job completed but did not return a flyer ID.';
-    }
-    return null;
-  };
+    let msg: string | null = null;
+    let dupId: number | null = null;
 
-  const errorMessage = getErrorMessage();
-  const duplicateFlyerId = (uploadMutation.error as any)?.body?.flyerId ?? null;
-  const flyerId = jobStatus?.state === 'completed' ? jobStatus.returnValue?.flyerId : null;
+    if (state === 'error') {
+      if (uploadMutation.isError) {
+        const uploadError = uploadMutation.error;
+        if (isApiError(uploadError)) {
+          msg = uploadError.body.message;
+          // Specifically handle 409 Conflict for duplicate flyers
+          if (uploadError.status === 409) {
+            dupId = uploadError.body.flyerId ?? null;
+          }
+        } else if (uploadError instanceof Error) {
+          msg = uploadError.message;
+        } else {
+          msg = 'An unknown upload error occurred.';
+        }
+      } else if (pollError) {
+        msg = `Polling failed: ${pollError.message}`;
+      } else if (jobStatus?.state === 'failed') {
+        msg = `Processing failed: ${jobStatus.progress?.message || jobStatus.failedReason || 'Unknown reason'}`;
+      } else if (jobStatus?.state === 'completed' && !jobStatus.returnValue?.flyerId) {
+        msg = 'Job completed but did not return a flyer ID.';
+      }
+    }
+
+    return {
+      processingState: state,
+      errorMessage: msg,
+      duplicateFlyerId: dupId,
+      flyerId: jobStatus?.state === 'completed' ? jobStatus.returnValue?.flyerId ?? null : null,
+      statusMessage: uploadMutation.isPending ? 'Uploading file...' : jobStatus?.progress?.message,
+    };
+  }, [uploadMutation, jobStatus, pollError]);
 
   return {
     processingState,
diff --git a/src/routes/admin.content.routes.test.ts b/src/routes/admin.content.routes.test.ts
index d1e9a181..a5d86bc9 100644
--- a/src/routes/admin.content.routes.test.ts
+++ b/src/routes/admin.content.routes.test.ts
@@ -1,7 +1,8 @@
 // src/routes/admin.content.routes.test.ts
-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { describe, it, expect, vi, beforeEach, afterAll } from 'vitest';
 import supertest from 'supertest';
 import type { Request, Response, NextFunction } from 'express';
+import path from 'path';
 import {
   createMockUserProfile,
   createMockSuggestedCorrection,
@@ -15,6 +16,7 @@ import type { SuggestedCorrection, Brand, UserProfile, UnmatchedFlyerItem } from
 import { NotFoundError } from '../services/db/errors.db'; // This can stay, it's a type/class not a module with side effects.
 import fs from 'node:fs/promises';
 import { createTestApp } from '../tests/utils/createTestApp';
+import { cleanupFiles } from '../tests/utils/cleanupFiles';
 
 // Mock the file upload middleware to allow testing the controller's internal check
 vi.mock('../middleware/fileUpload.middleware', () => ({
@@ -140,6 +142,26 @@ describe('Admin Content Management Routes (/api/admin)', () => {
     vi.clearAllMocks();
   });
 
+  afterAll(async () => {
+    // Safeguard to clean up any logo files created during tests.
+    const uploadDir = path.resolve(__dirname, '../../../flyer-images');
+    try {
+      const allFiles = await fs.readdir(uploadDir);
+      // Files are named like 'logoImage-timestamp-original.ext'
+      const testFiles = allFiles
+        .filter((f) => f.startsWith('logoImage-'))
+        .map((f) => path.join(uploadDir, f));
+
+      if (testFiles.length > 0) {
+        await cleanupFiles(testFiles);
+      }
+    } catch (error) {
+      if (error instanceof Error && (error as NodeJS.ErrnoException).code !== 'ENOENT') {
+        console.error('Error during admin content test file cleanup:', error);
+      }
+    }
+  });
+
   describe('Corrections Routes', () => {
     it('GET /corrections should return corrections data', async () => {
       const mockCorrections: SuggestedCorrection[] = [
diff --git a/src/routes/user.routes.test.ts b/src/routes/user.routes.test.ts
index a4c3eba3..026adeb9 100644
--- a/src/routes/user.routes.test.ts
+++ b/src/routes/user.routes.test.ts
@@ -1,7 +1,8 @@
 // src/routes/user.routes.test.ts
-import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { describe, it, expect, vi, beforeEach, afterAll } from 'vitest';
 import supertest from 'supertest';
 import express from 'express';
+import path from 'path';
 import fs from 'node:fs/promises';
 import {
   createMockUserProfile,
@@ -19,6 +20,7 @@ import { Appliance, Notification, DietaryRestriction } from '../types';
 import { ForeignKeyConstraintError, NotFoundError, ValidationError } from '../services/db/errors.db';
 import { createTestApp } from '../tests/utils/createTestApp';
 import { mockLogger } from '../tests/utils/mockLogger';
+import { cleanupFiles } from '../tests/utils/cleanupFiles';
 import { logger } from '../services/logger.server';
 import { userService } from '../services/userService';
 
@@ -166,6 +168,26 @@ describe('User Routes (/api/users)', () => {
     beforeEach(() => {
       // All tests in this block will use the authenticated app
     });
+
+    afterAll(async () => {
+      // Safeguard to clean up any avatar files created during tests.
+      const uploadDir = path.resolve(__dirname, '../../../uploads/avatars');
+      try {
+        const allFiles = await fs.readdir(uploadDir);
+        // Files are named like 'avatar-user-123-timestamp.ext'
+        const testFiles = allFiles
+          .filter((f) => f.startsWith(`avatar-${mockUserProfile.user.user_id}`))
+          .map((f) => path.join(uploadDir, f));
+
+        if (testFiles.length > 0) {
+          await cleanupFiles(testFiles);
+        }
+      } catch (error) {
+        if (error instanceof Error && (error as NodeJS.ErrnoException).code !== 'ENOENT') {
+          console.error('Error during user routes test file cleanup:', error);
+        }
+      }
+    });
     describe('GET /profile', () => {
       it('should return the full user profile', async () => {
         vi.mocked(db.userRepo.findUserProfileById).mockResolvedValue(mockUserProfile);
diff --git a/src/tests/integration/ai.integration.test.ts b/src/tests/integration/ai.integration.test.ts
index 1c612e0f..af4ceacc 100644
--- a/src/tests/integration/ai.integration.test.ts
+++ b/src/tests/integration/ai.integration.test.ts
@@ -40,17 +40,19 @@ describe('AI API Routes Integration Tests', () => {
     // 1. Clean up database records
     await cleanupDb({ userIds: [testUserId] });
 
-    // 2. Clean up any leftover files from the 'image' and 'images' multer instances.
-    // Most routes clean up after themselves, but this is a safeguard for failed tests.
+    // 2. Safeguard: Clean up any leftover files from failed tests.
+    // The routes themselves should clean up on success, but this handles interruptions.
     const uploadDir = path.resolve(__dirname, '../../../flyer-images');
     try {
-      const files = await fs.readdir(uploadDir);
-      // Target files created by the 'image' and 'images' multer instances.
-      const testFileNames = files.filter((f) => f.startsWith('image-') || f.startsWith('images-'));
-      const testFilePaths = testFileNames.map((f) => path.join(uploadDir, f));
-      await cleanupFiles(testFilePaths);
+      const allFiles = await fs.readdir(uploadDir);
+      const testFiles = allFiles
+        .filter((f) => f.startsWith('image-') || f.startsWith('images-'))
+        .map((f) => path.join(uploadDir, f));
+
+      if (testFiles.length > 0) {
+        await cleanupFiles(testFiles);
+      }
     } catch (error) {
-      // If readdir fails (e.g., directory doesn't exist), we can ignore it.
       if (error instanceof Error && (error as NodeJS.ErrnoException).code !== 'ENOENT') {
         console.error('Error during AI integration test file cleanup:', error);
       }
diff --git a/src/tests/utils/cleanup.ts b/src/tests/utils/cleanup.ts
index ac206ab1..4cb8b302 100644
--- a/src/tests/utils/cleanup.ts
+++ b/src/tests/utils/cleanup.ts
@@ -43,7 +43,7 @@ export const cleanupDb = async (ids: TestResourceIds) => {
       await pool.query('DELETE FROM public.user_watched_items WHERE user_id = ANY($1::uuid[])', [userIds]);
       await pool.query('DELETE FROM public.user_achievements WHERE user_id = ANY($1::uuid[])', [userIds]);
       await pool.query('DELETE FROM public.activity_log WHERE user_id = ANY($1::uuid[])', [userIds]);
-      await pool.query('DELETE FROM public.refresh_tokens WHERE user_id = ANY($1::uuid[])', [userIds]);
+      await pool.query('DELETE FROM public.user_refresh_tokens WHERE user_id = ANY($1::uuid[])', [userIds]);
       await pool.query('DELETE FROM public.password_reset_tokens WHERE user_id = ANY($1::uuid[])', [userIds]);
     }