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.

docs/requirements.md

@@ -248,6 +248,7 @@ Internal architecture, components, and application logic.
 | DR-091 | Search result groups split TV into separate Shows and Episodes groups and add a People group (default order: Shows → Episodes → Movies → Songs → Albums → Artists → People); a stored `tvShows` order from before the split expands in place to shows+episodes so an upgrading user keeps their arrangement | UI | UR-060 | Done |
 | DR-092 | Video tap gestures resolve in `tapGestures.ts` (pure, unit-tested) rather than inline in `VideoPlayer.svelte`: `registerTap` returns `pending` for a first tap — the component defers `togglePlayPause` behind a `DOUBLE_TAP_WINDOW_MS` (300 ms) timer that a second tap cancels — or `seek` (+30 s right / −10 s left) for a second tap inside the window; a consumed second tap resets the state so a third tap starts fresh, and a swipe cancels the pending tap. The compatibility `click` the browser synthesizes after a touch tap is filtered in `handleVideoClick` so it cannot bypass the deferral. `resolveSeekTarget` converts the delta to the absolute position the facade requires, clamped per DR-095 and chained off a still-in-flight `pendingSeekTarget` so back-to-back skips accumulate instead of all resolving against a not-yet-updated position | UI | UR-061 | Done |
 | DR-094 | Frontend boundary tripwire (`scripts/check-frontend-boundary.sh`) detects Jellyfin item-type array literals **anywhere** in `src/` rather than only inline at an `includeItemTypes:` query site, so a category→type mapping cannot evade the check by being assigned to a named const (the evasion that let the `scoped-search` leak pass CI); requires two adjacent type literals so single-type presentation and `item.type ===` inspection stay legal, and caps the allowlist to force taxonomy into Rust instead of accumulating exceptions | Tooling | - | Done |
+| DR-098 | Video tap gestures act **immediately** — no deferral, no timer, and only first/second taps exist. A first tap toggles play/pause; a second tap inside `DOUBLE_TAP_WINDOW_MS` seeks *and* toggles again, so the two toggles cancel and a double tap preserves the play state (playing → jump and keep playing; paused → jump and stay paused). This replaces a design that deferred the first tap behind a 300 ms timer so a second tap could cancel it: the timer cleared its own handle *before* invoking the toggle, which reopened the `tapTimeout !== null` guard in `handleVideoClick` meant to suppress the compatibility `click` Android's WebView synthesizes after a touch — the late click then toggled a second time, producing a pause/unpause loop (long-press was unaffected, which is what identified the tap path). Click suppression no longer depends on the timer: `handleVideoClick` ignores `detail === 0` *and* any click within `TOUCH_CLICK_SUPPRESS_MS` of a touch tap. A swipe undoes the touchstart toggle exactly once (latched on `swipeGestureActive`) so brightness swipes never change play state | UI | UR-061 | Done |
 | DR-097 | Transport authority (play/pause/toggle) lives in Rust for **webview-rendered** media, not just native. The controller tracks the state the HTML5 element reports (`html5_playing`, fed by `report_html5_state`, which now *stores* rather than only re-emitting); `play`/`pause`/`toggle_playback` consult it and drive the element by emitting a `ControlCommand` that `playerEvents.handleControlCommand` executes against the active adapter. A `stopped`/`idle` report clears it so the native backend (MPV/ExoPlayer) regains authority for music. The frontend facade no longer short-circuits transport into the adapter: `adapter.toggle()` previously decided play-vs-pause by reading `el.paused` off the DOM, a value that flips transiently while an element buffers or settles a seek — so two intents ~150 ms apart read *different* values, performed *opposing* actions, and self-sustained a play/pause loop needing no further input (observed on Android with a fully-buffered `readyState=4 networkState=1` element). Same "backend decides, adapter executes the primitive" split as `player_seek_video` | Player | UR-005 | Done |
 | DR-096 | `Html5PlayerAdapter.play()` is resilient to stall recovery: an in-flight attempt is memoised so concurrent callers (UI plus hls.js gap-controller recovery) share one `element.play()` instead of stacking calls, and an `AbortError` ("play() request was interrupted by a call to pause()") is logged at debug rather than pushed to `host.onError`. The browser raises it whenever a pending play promise is superseded by a pause/seek/source change, which hls.js does routinely while nudging past a stall — reporting it surfaced a player error roughly once per second for the whole stall and left the UI stuck showing paused | Player | UR-005 | Done |
 | DR-095 | Seek targets clamp strictly *inside* the media (`clampSeekTarget`, `END_SEEK_MARGIN_SECONDS` = 6 s ≈ one HLS segment) instead of to the exact `duration`. Landing on the duration makes hls.js request the segment whose start time lies past the end of the media (e.g. a 6330.324 s item → segment 1055 starting at 6336.33 s), which Jellyfin never produces; the fetch times out and hls.js' gap-controller stalls at the last buffered position, presenting as "unpausing or skipping bounces straight back to paused". Applied on both seek paths — the relative-skip `resolveSeekTarget` and the seek-bar drag, whose range input `max` is the duration itself — and floored at 0 so media shorter than the margin still seeks to the start | UI | UR-061 | Done |
@@ -411,10 +412,11 @@ Internal architecture, components, and application logic.
 | UT-082 | EQ fields serialize as camelCase (`equalizerEnabled`/`equalizerBands`) and round-trip | DR-030 | Done |
 | UT-083 | EQ filter entries are empty when disabled or when the curve is flat (clears the `af` filter) | IR-020 | Done |
 | UT-084 | Enabled EQ builds one peaking `equalizer` per non-zero band at the right frequency and gain inside a single `lavfi` chain | IR-020 | Done |
-| UT-085 | A first tap resolves to `pending`, not an immediate play/pause, and becomes `togglePlayPause` only once the double-tap window has elapsed | DR-092 | Done |
-| UT-086 | A second tap inside the window seeks (+30 s right half, −10 s left half) with the matching feedback side, and clears the deferred play/pause so a double tap never pauses | DR-092 | Done |
-| UT-087 | A tap after the window, and a third tap after a consumed double tap, each start a fresh pending tap; repeated double taps keep seeking; `cancel()` drops a pending tap so a swipe cannot pause | DR-092 | Done |
-| UT-088 | `resolveSeekTarget` applies the delta to the reported position, clamps to `[0, duration]`, chains off an in-flight pending target so rapid skips accumulate, and ignores that target once the player reports past it | DR-092 | Done |
+| UT-085 | A first tap resolves to `togglePlayPause` immediately — no deferral and no timer | DR-092, DR-098 | Done |
+| UT-086 | A second tap inside the window seeks (+30 s right half, −10 s left half) with the matching feedback side **and** re-toggles play/pause, so the two toggles cancel and the play state is unchanged by a double tap | DR-092, DR-098 | Done |
+| UT-087 | A tap after the window, and the tap following a consumed pair, are each fresh first taps that toggle (there is no third-tap case); repeated double taps keep seeking; `cancel()` makes the next tap a first tap so an interpreted swipe cannot seek | DR-092, DR-098 | Done |
+| UT-088 | `resolveSeekTarget` applies the delta to the reported position, clamps into `[0, duration - END_SEEK_MARGIN_SECONDS]`, chains off an in-flight pending target so rapid skips accumulate, and ignores that target once the player reports past it | DR-092, DR-095 | Done |
+| UT-091 | Transport intents (play/pause/toggle) reach the backend even while a video adapter is registered, and never call the adapter's own `play`/`pause`/`toggle` — the webview must not decide play-vs-pause from the DOM | DR-097 | Done |
 
 ### Integration Tests