feat: add active-game screen and firing interactions

data/target_interaction.js

@@ -0,0 +1,49 @@
+(() => {
+  function sameTarget(left, right) { return left?.x === right?.x && left?.y === right?.y; }
+
+  function createTargetActivator({ canFire, select, fire, thresholdMs = 360, now = () => Date.now() }) {
+    let lastTap;
+    let firing = false;
+
+    async function fireOnce(target) {
+      if (firing || !canFire(target)) return false;
+      firing = true;
+      lastTap = undefined;
+      try {
+        await fire(target);
+        return true;
+      } finally {
+        firing = false;
+      }
+    }
+
+    function tap(target) {
+      if (firing || !canFire(target)) return { action: 'ignored' };
+      const timestampMs = now();
+      if (lastTap && sameTarget(lastTap.target, target) && timestampMs - lastTap.timestampMs <= thresholdMs) {
+        return { action: 'fire', promise: fireOnce(target) };
+      }
+      select(target);
+      lastTap = { target, timestampMs };
+      return { action: 'select' };
+    }
+
+    function keyboard(target) {
+      if (firing || !canFire(target)) return { action: 'ignored' };
+      select(target);
+      lastTap = undefined;
+      return { action: 'select' };
+    }
+
+    return {
+      tap,
+      keyboard,
+      doubleActivate: (target) => ({ action: 'fire', promise: fireOnce(target) }),
+      isFiring: () => firing,
+    };
+  }
+
+  const api = { createTargetActivator };
+  if (typeof module !== 'undefined' && module.exports) module.exports = api;
+  else globalThis.BattleshipTargetInteraction = api;
+})();