🔧 Fix ESLint layer naming to match actual directory structure (#854)

Change "utility" to "utils" in ESLint configuration and documentation to align with the actual directory name defined in the architecture.

- Update ESLint file pattern from `src/lib/utility/**/*.ts` to `src/lib/utils/**/*.ts`
- Rename layer references from "Helpers/Utility" to "Helpers/Utils" in docs and error messages
- Ensure consistency between code, configuration, and documentation

Author: usagizmo

apps/web/README.md

@@ -38,7 +38,7 @@ src/lib/
 
 - **Components**: Access Helpers via Stores/LocalStores (direct Helper dependency is prohibited)
 - **Stores/LocalStores**: Can directly access Helpers, pass state to Helpers for execution
-- **Helpers/Utility**: Cannot depend on Stores (must be pure functions, receive values as arguments)
+- **Helpers/Utils**: Cannot depend on Stores (must be pure functions, receive values as arguments)
 
 ## State Management
 

apps/web/eslint.config.js

@@ -36,17 +36,17 @@ export default [
       ],
     },
   },
-  // Helpers and Utility layers cannot depend on Stores layer
+  // Helpers and Utils layers cannot depend on Stores layer
   {
-    files: ['src/lib/helpers/**/*.ts', 'src/lib/utility/**/*.ts'],
+    files: ['src/lib/helpers/**/*.ts', 'src/lib/utils/**/*.ts'],
     rules: {
       'no-restricted-imports': [
         'error',
         {
           patterns: [
             {
               group: ['$lib/stores', '$lib/stores/**'],
-              message: 'Pass values as arguments to keep Helpers/Utility pure functions',
+              message: 'Pass values as arguments to keep Helpers/Utils pure functions',
             },
           ],
         },

packages/eslint-config/README.md

@@ -73,11 +73,11 @@ The `web` configuration includes architectural layer rules to enforce clean sepa
 
 - **Stores Layer Access**: Direct imports from `$lib/stores/*` are prohibited; use `$lib/stores` index
 - **Components Layer**: Cannot directly import Helpers; must access via Stores/LocalStores
-- **Helpers/Utility Layers**: Cannot import from Stores layer; must be pure functions receiving values as arguments
+- **Helpers/Utils Layers**: Cannot import from Stores layer; must be pure functions receiving values as arguments
 
 These rules ensure:
 
-- **Testability**: Pure functions in Helpers/Utility layers are easy to test without mocking
+- **Testability**: Pure functions in Helpers/Utils layers are easy to test without mocking
 - **Maintainability**: Clear separation of concerns and unidirectional data flow
 - **Type Safety**: Dependency injection through function arguments provides better type inference