Add sign toggle button for score entry and email to title screen

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>

src/pages/EnterScores.module.css

@@ -27,6 +27,18 @@
   background: #fff5f5;
 }
 
+.signToggle {
+  width: 2.5rem;
+  height: 2.5rem;
+  border-radius: 50%;
+  border: 2px solid var(--color-parchment-border);
+  background: #fdfaf4;
+  font-size: 1.2rem;
+  font-weight: 600;
+  color: #555;
+  flex-shrink: 0;
+}
+
 .sumLine {
   margin: 0.5rem 0 0;
   text-align: center;

src/pages/EnterScores.tsx

@@ -17,6 +17,15 @@ export default function EnterScores({ game, onSubmit }: Props) {
     setValues(vs => vs.map((val, idx) => (idx === i ? v : val)))
   }
 
+  function toggleSign(i: number) {
+    setValues(vs => vs.map((val, idx) => {
+      if (idx !== i) return val
+      const digits = val.startsWith('-') ? val.slice(1) : val
+      if (!digits) return val
+      return val.startsWith('-') ? digits : '-' + digits
+    }))
+  }
+
   const parsed = values.map(v => parseInt(v, 10))
   const fieldError = values.map((v, i) => v !== '' && (isNaN(parsed[i]) || !isIndividualScoreValid(parsed[i])))
   const allFilled = parsed.every(n => !isNaN(n))
@@ -35,9 +44,12 @@ export default function EnterScores({ game, onSubmit }: Props) {
       {game.players.map((name, i) => (
         <div key={i} className={styles.row}>
           <span className={styles.name}>{name}</span>
+          <button type="button" className={styles.signToggle} onClick={() => toggleSign(i)}>
+            {values[i].startsWith('-') ? '−' : '+'}
+          </button>
           <input
             className={`${styles.scoreInput}${fieldError[i] ? ` ${styles.scoreInputError}` : ''}`}
-            type="number"
+            type="text"
             inputMode="numeric"
             value={values[i]}
             onChange={e => updateValue(i, e.target.value)}

src/pages/TitleScreen.module.css

@@ -26,6 +26,14 @@
   line-height: 0.9;
 }
 
+.email {
+  font-size: 0.8rem;
+  font-weight: 300;
+  color: #1a1a1a;
+  margin-top: 0.75rem;
+  letter-spacing: 0.03em;
+}
+
 .buttonRow {
   position: absolute;
   bottom: 2rem;

src/pages/TitleScreen.tsx

@@ -11,6 +11,7 @@ export default function TitleScreen({ onNewGame }: Props) {
       <div className={styles.title}>
         <span className={styles.titleWord}>Black</span>
         <span className={styles.titleNumber}>7</span>
+        <span className={styles.email}>ross.andrews@gmail.com</span>
       </div>
       <div className={styles.buttonRow}>
         <PrimaryButton onClick={onNewGame}>New Game</PrimaryButton>