fix(player): controls bar taps are not player gestures (DR-098)

The bottom play/pause button did nothing. The gesture listener lives on
the outer container and touch events bubble, so tapping the button ran
handleTouchStart (toggle #1) and then the button's own onclick (toggle
#2). The two cancelled out, leaving the control apparently dead.

Ignore container-level gestures for touches that land on an interactive
control: buttons, links, inputs (the seek bar), or anything inside the
controls bar, now marked `data-player-controls`. The rule itself is a
pure function over the ancestor chain (isControlSurfaceTouch), so it is
unit tested without a DOM.

Same root shape as the play-overlay bug in the previous commit: a second
click target over the video that the gesture layer did not account for.

src/lib/components/player/tapGestures.ts

@@ -31,6 +31,28 @@ export const DOUBLE_TAP_WINDOW_MS = 300;
  */
 export const TOUCH_CLICK_SUPPRESS_MS = 700;
 
+/**
+ * Whether a touch landed on an interactive control rather than the bare video
+ * surface, and so must NOT be interpreted as a play/pause or seek gesture.
+ *
+ * The gesture listener sits on the outer container, and touch events bubble, so
+ * without this a tap on the bottom control bar runs the gesture handler (toggle
+ * #1) *and* the button's own click handler (toggle #2) — the two cancel out and
+ * the button appears dead. Buttons, links, inputs (the seek bar), and anything
+ * inside an element marked `data-player-controls` are treated as controls.
+ *
+ * Takes the ancestor chain as plain tag/attribute pairs so the rule is unit
+ * testable without a DOM.
+ */
+export function isControlSurfaceTouch(
+  ancestors: Array<{ tag: string; isPlayerControls?: boolean }>
+): boolean {
+  const INTERACTIVE = new Set(["button", "a", "input", "select", "textarea", "label"]);
+  return ancestors.some(
+    (node) => node.isPlayerControls === true || INTERACTIVE.has(node.tag.toLowerCase())
+  );
+}
+
 /**
  * Whether a `click` should be ignored because a touch tap already handled it.
  *