Why

The engine needs a small declarative contract for turn-based gameplay patterns without introducing executable custom rules. Authors need to describe a level-scoped automaton with a subject/property rule and repeatable movement pattern, while players and tools need deterministic phase state, visible beat feedback, and safe mod sharing.

What Changes

• Add an optional level automaton with { id, subject?, property, pattern, phase? } data.
• Define pattern as object steps: { action: 'move', dx, dy, cue?, sound? } or { action: 'wait', cue?, sound? }.
• Activate the automaton's property dynamically when the level's board contains SUBJECT IS PROPERTY.
• Advance numeric phase once per accepted player turn, including explicit wait; blocked input does not advance it.
• Include automata state in settled state, Undo/reset snapshots, replay, and solver state; report automated movement in automated event entries.
• Validate local CommonJS and data-only shared automata and derive visible current/next beat feedback from normalized phase and pattern data.

Capabilities

New Capabilities

• rule-driven-automata: declarative pattern steps, level-scoped activation, phase state, validation/sharing, deterministic tools, and visual feedback.

Modified Capabilities

None. Existing board sentence rules and MVP vocabulary remain the source of activation; the automaton is additive level data.

Impact

• Affected level state, settled events, mod validation, data-only sharing, Undo/reset, replay, solver state keys, and presentation feedback.
• No executable callbacks, completion predicates, arbitrary shared code, or new pattern string shorthand are introduced.
• Existing levels without an automaton remain unchanged.