FIX: Type Safety, Environment Validation, Redis Integration Tests, an…

.github/workflows/backend-ci.yml

@@ -91,6 +91,16 @@ jobs:
         working-directory: ./backend
         run: npm run build
 
+      # Dependency vulnerability scanning with npm audit.
+      # Fails the build if high or critical vulnerabilities are found in the dependency tree.
+      # The --audit-level=high threshold balances security with practicality — low/moderate
+      # findings are logged but don't block CI, giving teams time to evaluate and update
+      # dependencies on a reasonable schedule rather than forcing immediate action on every
+      # minor advisory.
+      - name: Dependency vulnerability scan
+        working-directory: ./backend
+        run: npm audit --audit-level=high
+
       - name: Upload coverage
         uses: codecov/codecov-action@v4
         with:

backend/.eslintrc.js

@@ -20,7 +20,7 @@ module.exports = {
     "@typescript-eslint/interface-name-prefix": "off",
     "@typescript-eslint/explicit-function-return-type": "off",
     "@typescript-eslint/explicit-module-boundary-types": "off",
-    "@typescript-eslint/no-explicit-any": "off",
+    "@typescript-eslint/no-explicit-any": ["warn", { ignoreRestArgs: false }],
     "@typescript-eslint/no-unused-vars": ["warn", { argsIgnorePattern: "^_" }],
   },
 };