fix(player): tap gestures act immediately, no deferral timer (DR-098)

Tapping the video surface pause-looped: it would unpause and bounce
straight back to paused about a second later. Long-press unpaused fine,
which is what pinned it to the tap path rather than the media pipeline.

The gesture handler deferred the first tap's play/pause behind a 300ms
timer so a second tap could cancel it and seek instead. But the timer
callback cleared its own handle *before* invoking the toggle, and
handleVideoClick used exactly that handle (`tapTimeout !== null`) to
suppress the compatibility click Android's WebView synthesizes after a
touch. So the guard was already open when the late click arrived, and it
toggled a second time.

Replace the deferral with immediate action — there are only first and
second taps:

  1st tap: toggle play/pause
  2nd tap: seek, then toggle play/pause again

The second toggle undoes the first, so a double tap seeks while leaving
the play state exactly as it was: playing jumps and keeps playing,
paused jumps and stays paused. No timer, no window race, no loop.

Click suppression no longer depends on the timer: ignore detail === 0
and any click within 700ms of a touch tap, since Android can deliver the
synthesized click late and with a real detail value.

A swipe now undoes the touchstart toggle (latched on swipeGestureActive
so it happens once, not per touchmove frame), keeping brightness swipes
from changing the play state.

UT-085..087 described the old deferred behaviour and are updated to the
new contract. UT-091 is used for the DR-097 facade tests, since UT-089
and UT-090 were already claimed by extract-traces.test.ts.

src/lib/components/player/VideoPlayer.svelte

@@ -112,7 +112,10 @@
   let touchStartY = $state(0);
   let touchStartTime = $state(0);
   let tapGestures = createTapGestureState();
-  let tapTimeout: ReturnType<typeof setTimeout> | null = null;
+  // When a touch tap last ran the gesture handler, so the compatibility click
+  // the browser synthesizes afterwards can be ignored (see handleVideoClick).
+  let lastTouchTapAt = 0;
+  const TOUCH_CLICK_SUPPRESS_MS = 700;
   let brightness = $state(1); // 0-2, default 1
   let showDoubleTapFeedback = $state<TapFeedback | null>(null);
   let doubleTapFeedbackTimeout: ReturnType<typeof setTimeout> | null = null;
@@ -719,11 +722,6 @@
     if (debugLogInterval) {
       clearInterval(debugLogInterval);
     }
-    // A deferred single tap must not fire play/pause after teardown.
-    if (tapTimeout) {
-      clearTimeout(tapTimeout);
-      tapTimeout = null;
-    }
     tapGestures.cancel();
     if (doubleTapFeedbackTimeout) {
       clearTimeout(doubleTapFeedbackTimeout);
@@ -1457,25 +1455,22 @@
       now: Date.now(),
     });
 
-    if (tapTimeout) {
-      clearTimeout(tapTimeout);
-      tapTimeout = null;
-    }
+    // Suppress the compatibility click this touch will synthesize.
+    lastTouchTapAt = Date.now();
 
     if (outcome.action === "seek") {
       e.preventDefault();
       handleDoubleTap(outcome.seekSeconds, outcome.feedback);
+      // Re-toggle so the first tap's toggle is undone: a double tap seeks and
+      // leaves the play state as it was (playing keeps playing, paused stays
+      // paused).
+      if (outcome.togglePlayPause) togglePlayPause();
       return;
     }
 
-    // Single tap so far: defer play/pause until the double-tap window closes,
-    // so a double tap seeks without also toggling pause.
-    tapTimeout = setTimeout(() => {
-      tapTimeout = null;
-      if (tapGestures.resolvePending(Date.now())) {
-        togglePlayPause();
-      }
-    }, outcome.pendingAfterMs);
+    // First tap: act now. Nothing is deferred, so there is no timer to race the
+    // compatibility click Android synthesizes after a touch tap (see DR-098).
+    togglePlayPause();
   }
 
   function handleTouchMove(e: TouchEvent) {
@@ -1488,14 +1483,16 @@
 
     // Minimum movement to register as swipe (50px)
     if (Math.abs(deltaY) > 50 && timeDelta > 50) {
-      swipeGestureActive = true;
-
-      // This is a swipe, not a tap — drop the deferred play/pause.
-      tapGestures.cancel();
-      if (tapTimeout) {
-        clearTimeout(tapTimeout);
-        tapTimeout = null;
+      // Only on the frame the gesture is first recognised as a swipe — this runs
+      // on every touchmove, and the correction below must happen exactly once.
+      if (!swipeGestureActive) {
+        // The touchstart already toggled play/pause (taps act immediately now),
+        // so undo it: a swipe must not change the play state. Forget the tap too,
+        // so it cannot pair with a later tap into a spurious seek.
+        togglePlayPause();
+        tapGestures.cancel();
       }
+      swipeGestureActive = true;
 
       // Brightness control on vertical swipe
       swipeType = "brightness";
@@ -1514,14 +1511,19 @@
   }
 
   /**
-   * Mouse clicks toggle play/pause immediately. Touch taps are already handled
-   * by `handleTouchStart` (which defers play/pause past the double-tap window),
-   * so the compatibility click that follows a tap must be ignored here —
-   * otherwise it pauses on the first tap of a double tap.
+   * Mouse clicks toggle play/pause immediately. Touch taps are handled fully by
+   * `handleTouchStart`, so the compatibility click the browser synthesizes after
+   * a tap must be ignored here or every tap toggles twice.
+   *
+   * Two independent guards, because neither alone is sufficient: `detail === 0`
+   * catches the synthesized click on engines that report it, and the recency
+   * check covers engines that report a real `detail` — Android's WebView can
+   * deliver the click well after the touch, which is what defeated the previous
+   * timer-based guard (see DR-098).
    */
   function handleVideoClick(e: MouseEvent) {
-    // A click synthesized from a touch reports no pointer movement detail.
-    if (e.detail === 0 || tapTimeout !== null) return;
+    if (e.detail === 0) return;
+    if (Date.now() - lastTouchTapAt < TOUCH_CLICK_SUPPRESS_MS) return;
     togglePlayPause();
   }