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/player/transport.authority.test.ts

@@ -1,7 +1,7 @@
 /**
  * Transport authority: play/pause/toggle are DECIDED in Rust, never in the webview.
  *
- * TRACES: UR-005 | DR-097 | UT-089
+ * TRACES: UR-005 | DR-097 | UT-091
  *
  * The frontend used to short-circuit transport controls whenever a video adapter
  * was registered: `toggle()` read `el.paused` off the DOM and flipped the element