Migrate cursor rules (#12646)

Migrating rules to new format but they should be re-written entirely, I
don't think they help much and are not auto-included (except
architecture)

.cursor/rules/file-structure.mdc

@@ -0,0 +1,107 @@
+---
+description: 
+globs: 
+alwaysApply: false
+---
+# File Structure Guidelines
+
+## Directory Organization
+```
+packages/twenty-front/src/
+├── components/      # Reusable UI components
+├── pages/          # Route components  
+├── modules/        # Feature modules
+├── hooks/          # Custom hooks
+├── services/       # API services
+└── types/          # Type definitions
+
+packages/twenty-server/src/
+├── modules/        # Feature modules
+├── entities/       # Database entities
+├── dto/           # Data transfer objects
+└── utils/         # Helper functions
+```
+
+## File Naming
+- **kebab-case** for all files and directories
+- **Descriptive suffixes** for clarity
+```
+// ✅ Correct naming
+user-profile.component.tsx
+user-profile.styles.ts
+user-profile.test.tsx
+user.service.ts
+user.entity.ts
+create-user.dto.ts
+```
+
+## Index Files & Barrel Exports
+```typescript
+// ✅ Clean barrel exports in index.ts
+export { UserCard } from './user-card.component';
+export { UserList } from './user-list.component';
+export type { UserCardProps, UserListProps } from './types';
+
+// ✅ Usage - clean imports
+import { UserCard, UserList } from '@/components/user';
+```
+
+## Module Structure
+```
+src/modules/user/
+├── components/     # Module-specific components
+├── hooks/         # Module hooks
+├── services/      # API services
+├── types/         # Type definitions
+└── index.ts       # Module exports
+```
+
+## Import/Export Patterns
+```typescript
+// ✅ Import organization
+// 1. External libraries
+import React from 'react';
+import styled from 'styled-components';
+
+// 2. Internal modules (absolute paths)
+import { Button } from '@/components/ui';
+import { UserService } from '@/services';
+
+// 3. Relative imports
+import { UserCardProps } from './types';
+
+// ✅ Named exports only (no default exports)
+export const UserComponent = ({ user }: UserProps) => {
+  // Component implementation
+};
+```
+
+## File Size Guidelines
+- **Components**: Under 300 lines
+- **Services**: Under 500 lines  
+- **Extract logic** into hooks/utilities when files grow large
+- **Use composition** over large monolithic components
+
+## Configuration Files
+
+### Project Configuration
+```
+.vscode/                       # VSCode settings
+├── settings.json
+├── extensions.json
+└── launch.json
+
+.github/                       # GitHub workflows
+├── workflows/
+└── templates/
+
+.cursor/                       # Cursor rules
+├── rules/
+└── environment.json
+```
+
+### Build Configuration
+- Keep build configs in root or package directories
+- Use consistent naming for config files
+- Comment complex configurations
+- Version control all configuration files