feat: enforce @/ alias for imports and fix all relative parent imports (#16787)

## Summary
This PR enforces the use of `@/` alias for imports instead of relative
parent imports (`../`).

## Changes

### ESLint Configuration
- Added `no-restricted-imports` pattern in `eslint.config.react.mjs` to
block `../*` imports with the message "Relative parent imports are not
allowed. Use @/ alias instead."
- Removed the non-working `import/no-relative-parent-imports` rule
(doesn't work properly in ESLint flat config)

### VS Code Settings
- Added `javascript.preferences.importModuleSpecifier: non-relative` to
`.vscode/settings.json` (TypeScript setting was already there)

### Code Fixes
- Fixed **941 relative parent imports** across **706 files** in
`packages/twenty-front`
- All `../` imports converted to use `@/` alias

## Why
- Consistent import style across the codebase
- Easier to move files without breaking imports
- Better IDE support for auto-imports
- Clearer understanding of where imports come from

packages/twenty-front/src/modules/settings/data-model/objects/components/SettingsObjectCoverImage.tsx

@@ -7,8 +7,8 @@ import { IconEye } from 'twenty-ui/display';
 import { FloatingButton } from 'twenty-ui/input';
 import { Card } from 'twenty-ui/layout';
 
-import DarkCoverImage from '../../assets/cover-dark.png';
-import LightCoverImage from '../../assets/cover-light.png';
+import DarkCoverImage from '@/settings/data-model/assets/cover-dark.png';
+import LightCoverImage from '@/settings/data-model/assets/cover-light.png';
 
 const StyledCoverImageContainer = styled(Card)`
   align-items: center;

packages/twenty-front/src/modules/settings/data-model/objects/components/__stories__/SettingsObjectInactiveMenuDropDown.stories.tsx

@@ -3,7 +3,7 @@ import { expect, fn, userEvent, within } from '@storybook/test';
 
 import { ComponentDecorator } from 'twenty-ui/testing';
 import { I18nFrontDecorator } from '~/testing/decorators/I18nFrontDecorator';
-import { SettingsObjectInactiveMenuDropDown } from '../SettingsObjectInactiveMenuDropDown';
+import { SettingsObjectInactiveMenuDropDown } from '@/settings/data-model/objects/components/SettingsObjectInactiveMenuDropDown';
 
 const handleActivateMockFunction = fn();
 const handleDeleteMockFunction = fn();