Roadmap

The engine is production-minded and complete for the shipped scope. Natural next steps, roughly in priority order:

Multiplayer hardening

• Server-authoritative hidden information. Filter per-player views so a synced snapshot can’t leak a hidden hand (a Cloud Function host, or move validation in a trusted function). Today’s sync shares full state.
• Spectators and rejoin-by-seat (claim an empty seat on reconnect).
• Server-validated moves for anti-cheat, reusing the existing Cloud-Functions pattern from the rest of the repo.

Engine

• Replay player UI on top of the existing action log (the data is already recorded by MatchClient.getLog()).
• Simultaneous-action phases (e.g. everyone picks at once) — currently strictly sequential turns.
• Timed turns / clocks as an engine-level option.
• Hex grids alongside the square grid (the board API is ready to extend).

UX & content

• Drag-and-drop card/piece movement (click/keyboard is the baseline today).
• More demo games (trick-taking, set-collection, area-control) to widen the reference set.
• A fourth theme and printable/exportable game results.

Tooling

• Optional engine extraction into a standalone published package (the module boundary already permits it).
• Property-based tests for reducer invariants.

Contributions slot in cleanly: most of the above touch one layer at a time thanks to the strict module boundaries.