fix(lint): Add ctx shim to routes/apps and routes/arr

- routes/apps/deploy.js: Add ctx shim with APP_TEMPLATES, siteConfig, buildDomain, buildServiceUrl, addServiceToConfig, dns, notification, safeErrorMessage
- routes/apps/index.js: Extract additional ctx properties for sub-routes
- routes/arr/config.js: Add ctx shim with notification, safeErrorMessage + logError import
- routes/arr/index.js: Extract notification, safeErrorMessage for sub-routes

Result: Fixed ~30 no-undef errors (deploy.js 0 errors, arr/config.js 0 errors)

dashcaddy-api/.eslintrc.js

@@ -0,0 +1,57 @@
+module.exports = {
+  env: {
+    node: true,
+    es2021: true,
+  },
+  extends: 'eslint:recommended',
+  parserOptions: {
+    ecmaVersion: 'latest',
+    sourceType: 'commonjs',
+  },
+  rules: {
+    // Error Prevention
+    'no-unused-vars': ['warn', { argsIgnorePattern: '^_', varsIgnorePattern: '^_' }],
+    'no-console': 'off', // We use structured logging, but console is okay for debug
+    'no-undef': 'error',
+    'no-unreachable': 'error',
+    'no-constant-condition': ['error', { checkLoops: false }],
+
+    // Code Quality
+    'prefer-const': 'warn',
+    'no-var': 'warn',
+    'eqeqeq': ['warn', 'always', { null: 'ignore' }],
+    'curly': ['warn', 'multi-line'],
+    'no-throw-literal': 'error',
+
+    // Async/Await
+    'require-await': 'warn',
+    'no-async-promise-executor': 'error',
+    'no-await-in-loop': 'off', // Sometimes intentional for sequential operations
+
+    // Style (Prettier handles formatting, these are semantic)
+    'consistent-return': 'off', // Express routes don't always return
+    'no-nested-ternary': 'warn',
+    'max-depth': ['warn', 4],
+    'complexity': ['warn', 20],
+
+    // Prevent common pitfalls
+    'no-eval': 'error',
+    'no-implied-eval': 'error',
+    'no-new-func': 'error',
+    'no-with': 'error',
+    'no-proto': 'error',
+  },
+  overrides: [
+    {
+      // Test files can be more lenient
+      files: ['**/__tests__/**/*.js', '**/*.test.js', '**/*.spec.js'],
+      env: {
+        jest: true,
+      },
+      rules: {
+        'no-unused-expressions': 'off',
+        'max-depth': 'off',
+      },
+    },
+  ],
+};