diff --git a/backend/.coverage b/backend/.coverage
deleted file mode 100644
index 811e3bd30..000000000
Binary files a/backend/.coverage and /dev/null differ
diff --git a/frontend/eslint.config.js b/frontend/eslint.config.js
index 4f353f6ae..2cea7df7b 100644
--- a/frontend/eslint.config.js
+++ b/frontend/eslint.config.js
@@ -6,7 +6,7 @@ import tseslint from 'typescript-eslint'
 import { defineConfig, globalIgnores } from 'eslint/config'
 
 export default defineConfig([
-  globalIgnores(['dist']),
+  globalIgnores(['dist', 'coverage']),
   {
     files: ['**/*.{ts,tsx}'],
     extends: [
diff --git a/frontend/src/__tests__/api/githubBackupApi.test.ts b/frontend/src/__tests__/api/githubBackupApi.test.ts
index 851ba074b..d134ae3bd 100644
--- a/frontend/src/__tests__/api/githubBackupApi.test.ts
+++ b/frontend/src/__tests__/api/githubBackupApi.test.ts
@@ -2,7 +2,7 @@
  * Tests for the GitHub Backup API client functions.
  */
 
-import { describe, it, expect, beforeEach, vi } from 'vitest';
+import { describe, it, expect } from 'vitest';
 import { http, HttpResponse } from 'msw';
 import { setupServer } from 'msw/node';
 import type {
diff --git a/frontend/src/pages/SettingsPage.tsx b/frontend/src/pages/SettingsPage.tsx
index 70ad3e688..944babd95 100644
--- a/frontend/src/pages/SettingsPage.tsx
+++ b/frontend/src/pages/SettingsPage.tsx
@@ -544,14 +544,16 @@ export function SettingsPage() {
   // Local state for camera URL inputs (to avoid saving on every keystroke)
   const [localCameraUrls, setLocalCameraUrls] = useState<Record<number, string>>({});
   const cameraUrlSaveTimeoutRef = useRef<Record<number, ReturnType<typeof setTimeout>>>({});
+  const initializedPrinterUrlsRef = useRef<Set<number>>(new Set());
 
   // Initialize local camera URLs from printer data
   useEffect(() => {
     if (printers) {
       const urls: Record<number, string> = {};
       printers.forEach(p => {
-        if (p.external_camera_url && localCameraUrls[p.id] === undefined) {
+        if (p.external_camera_url && !initializedPrinterUrlsRef.current.has(p.id)) {
           urls[p.id] = p.external_camera_url;
+          initializedPrinterUrlsRef.current.add(p.id);
         }
       });
       if (Object.keys(urls).length > 0) {
diff --git a/test_frontend.sh b/test_frontend.sh
index 577555226..94157fea8 100755
--- a/test_frontend.sh
+++ b/test_frontend.sh
@@ -1,5 +1,6 @@
 #!/bin/sh
 
 cd frontend
+npm run lint
 npm test
 cd ..