# Spec Delta

## ADDED Requirements

### Requirement: Additional built-in patterns are available
The system SHALL provide additional built-in patterns (Beacon, Loaf, Boat, Tub, R-pentomino, Acorn) selectable via keys 5-0.

#### Scenario: Select beacon
- **WHEN** the user triggers `select:beacon`
- **THEN** a beacon preview is shown

### Requirement: New patterns support rotation
The system SHALL support 90-degree rotation for all new patterns.

#### Scenario: Rotate new pattern
- **WHEN** the user rotates a new pattern preview
- **THEN** its cells rotate accordingly