# Project Startup Rules

## Development Server
IMPORTANT: Always follow these instructions exactly when starting the development server:

```bash
lsof -ti :8000 | xargs kill -9; find . -type d -name "__pycache__" -exec rm -r {} +; uv run manage.py tailwind runserver
```

Note: These steps must be executed in this exact order as a single command to ensure consistent behavior.

## Package Management
IMPORTANT: When a Python package is needed, only use UV to add it:
```bash
uv add <package>
```
Do not attempt to install packages using any other method.

## Django Management Commands
IMPORTANT: When running any Django manage.py commands (migrations, shell, etc.), always use UV:
```bash
uv run manage.py <command>
```
This applies to all management commands including but not limited to:
- Making migrations: `uv run manage.py makemigrations`
- Applying migrations: `uv run manage.py migrate`
- Creating superuser: `uv run manage.py createsuperuser`
- Starting shell: `uv run manage.py shell`

NEVER use `python manage.py` or `uv run python manage.py`. Always use `uv run manage.py` directly.

## Entity Relationship Rules
IMPORTANT: Follow these entity relationship patterns consistently:

# Park Relationships
- Parks MUST have an Operator (required relationship)
- Parks MAY have a PropertyOwner (optional, usually same as Operator)
- Parks CANNOT directly reference Company entities

# Ride Relationships
- Rides MUST belong to a Park (required relationship)
- Rides MAY have a Manufacturer (optional relationship)
- Rides MAY have a Designer (optional relationship)
- Rides CANNOT directly reference Company entities

# Entity Definitions
- Operators: Companies that operate theme parks (replaces Company.owner)
- PropertyOwners: Companies that own park property (new concept, optional)
- Manufacturers: Companies that manufacture rides (replaces Company for rides)
- Designers: Companies/individuals that design rides (existing concept)

# Relationship Constraints
- Operator and PropertyOwner are usually the same entity but CAN be different
- Manufacturers and Designers are distinct concepts and should not be conflated
- All entity relationships should use proper foreign keys with appropriate null/blank settings