Replaces type="number" with type="text" + inputMode="numeric" so iOS
shows the numpad. A +/− toggle button beside each field handles the
sign; it is a no-op when the field is empty. Also adds contact email
below the title on the title screen.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Each player gets a number input; scores are validated individually
(divisible by 5, ≤ 110) and as a round (must sum to −110). Submit
stays disabled until all constraints pass. A running sum indicator
turns green when the round is valid. Submitting appends the round
to game state and persists it to localStorage.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>