Refactor to enforce AuthContext usage over useAuthStore and improve test stability

- Replaced `useAuthStore` with `useAuth` from `AuthContext` across frontend components and tests to ensure dependency injection compliance.
- Enhanced E2E test stability by delaying navigation until the auth context is fully initialized.
- Updated Playwright configuration to use a single worker to prevent mock conflicts.
- Refactored test setup to consistently inject `AuthProvider` for improved isolation and mocking.
- Adjusted comments and documentation to clarify dependency injection and testability patterns.

frontend/eslint.config.mjs

@@ -24,6 +24,21 @@ const eslintConfig = [
       "**/*.gen.tsx",
     ],
   },
+  {
+    rules: {
+      // Enforce Dependency Injection pattern for auth store
+      // Components/hooks must use useAuth() from AuthContext, not useAuthStore directly
+      // This ensures testability via DI (E2E mocks, unit test props)
+      // Exception: Non-React contexts (client.ts) use dynamic import + __TEST_AUTH_STORE__ check
+      "no-restricted-imports": ["error", {
+        "patterns": [{
+          "group": ["**/stores/authStore"],
+          "importNames": ["useAuthStore"],
+          "message": "Import useAuth from '@/lib/auth/AuthContext' instead. Direct authStore imports bypass dependency injection and break test mocking."
+        }]
+      }]
+    }
+  }
 ];
 
 export default eslintConfig;