Add FF/REW tap seeking and independent playback navigation options

ci/plex-requests.ini

@@ -249,6 +249,12 @@ class = whole
 reason = The subtitle agent's candidates for one item, read whole; the endpoint takes no window.
 evidence = rust-modules/plex/src/plex/subtitles.rs:129
 
+[queue_window.rs::play_queue_window]
+class = bounded
+parameter = window
+reason = Reads the existing queue around a target item; each handoff moves the window so navigation continues beyond the first response.
+evidence = rust-modules/plex/src/plex/queue_window.rs:16
+
 [timeline.rs::create_play_queue]
 class = whole
 reason = The play queue the server opens with continuous=1, kept whole; the server picks its window.

ci/test_build_gc.py

@@ -47,17 +47,29 @@ def run_guarded(argv, cwd, env, timeout=HANG_GUARD_SECS):
     the script's stages run in `$(...)` and python children that inherit those pipes: a hung grandchild
     keeps them open and the "timeout" blocks forever in `communicate()`. The child is therefore started
     as its own session and process-group leader, and on timeout the whole group - which this call
-    created, so the pgid is the pid it started - is killed before `TimeoutExpired` is raised."""
+    created, so the pgid is the pid it started - is killed before `TimeoutExpired` is raised.
+    A shell can fork during the first group kill; retry with a bounded pipe drain instead of
+    replacing the original timeout with an unbounded `communicate()`."""
     proc = subprocess.Popen(argv, cwd=cwd, env=env, text=True, stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE, stdin=subprocess.DEVNULL, start_new_session=True)
     try:
         out, err = proc.communicate(timeout=timeout)
     except subprocess.TimeoutExpired:
-        try:
-            os.killpg(proc.pid, signal.SIGKILL)
-        except OSError:
-            pass
-        proc.communicate()
+        for _ in range(10):
+            try:
+                os.killpg(proc.pid, signal.SIGKILL)
+            except OSError:
+                pass
+            try:
+                proc.communicate(timeout=1)
+                break
+            except subprocess.TimeoutExpired:
+                continue
+        else:
+            # A pipe held outside the owned group must still not hang the entire test runner.
+            proc.stdout.close()
+            proc.stderr.close()
+            proc.wait(timeout=1)
         raise
     return subprocess.CompletedProcess(argv, proc.returncode, out, err)
 
@@ -198,7 +210,7 @@ def test_a_run_whose_grandchild_holds_the_pipes_is_still_ended_by_the_guard(self
         started = time.monotonic()
         with self.assertRaises(subprocess.TimeoutExpired):
             run_guarded(["sh", "-c", "sleep 3600 & echo $! > " + shlex.quote(str(pidfile)) + "; wait"],
-                        self.root, os.environ.copy(), timeout=2)
+                        self.root, os.environ.copy(), timeout=5)
         self.assertLess(time.monotonic() - started, 60)
         pid = int(pidfile.read_text())
         deadline = time.monotonic() + 10

docs/parity-gaps.md

@@ -1239,6 +1239,7 @@ player, transport and tracks auditors, and is counted once in the themes above.
   *Verified:* CONFIRMED verbatim. rust-modules/src/app.rs:1405 handles `vis && hud_nav.focus == 1 && !ctrl.is_discs()`; app.rs:1409 is an empty `} else if vis && hud_nav.focus == 1 {` whose block closes on line 1410, so app.rs:1410-1413 (`track_menu::open_tab` + `route = Route::Player { overlay: Overlay::Menu }`) is unreachable for the ONLY condition that can still reach it (the discs). `git diff rust-modules/src/app.rs` confirms provenance: the pre-branch code was a single `if vis && hud_nav.focus == 1 {`, and the uncommitted skip-pill/Up-Next work split it into the guarded arm plus the stray empty one. Co
 
 - **No play/pause transport button and no previous/next-item buttons — the entire CENTER cluster is missing** — `major` / `medium`
+  *Fork update (2026-10-25):* Previous/Next now share the default disc row for an episode with a neighbour in its PlayQueue; there is no setting for them. Instant D-pad seeking is a separate opt-in setting, Off by default; dedicated FF/REW taps jump without it. Queue rows survive item handoffs, preserving Previous. The comparison below predates this work. See [Playback navigation](playback-navigation.md).
   Plex HTPC's centre cluster is |◀ / a large white FILLED circular play-pause (the only filled control on the HUD) / ▶|. We draw none of them. Play/pause exists only as an unlabelled fallthrough — OK when HUD focus is not on a control row (app.rs:1422-1430) or a pointer click on empty video (app.rs:1697-1705) — and the only play-state affordance drawn is a small NON-interactive Pause glyph beside the elapsed clock, documented at its call site as 'a state read-out, not an action toggle' (player_hud.rs:446-464). There is therefore no focusable, hit-testable play/pause anywhere, and no way to jump to the next or previous episode from the transport: Up Next only appears once the playhead is inside a credits marker AND a successor is queued (player_hud.rs:252-264), so mid-episode there is no next-item control at all, and previous-item does not exist in any form.
   *Where:* ui/player_hud.rs:333-486 for the drawn cluster + a hit-test beside `icon_hit` (player_hud.rs:289-297); ui/widgets.rs `CircleButton` already gives the disc look (focus-driven `ControlStyle::Accent` — the always-filled `Primary` style was retired in the 2026-08-13 palette sync). Next-item can reuse `route::up_next()` + `app.rs::play_up_next` (app.rs:824-845) unchanged. Previous-item needs `plex::Client::create_play_queue` (plex/timeline.rs:52-70) to also return the row BEFORE the selected one.
   *Device:* Play/pause and next-item are cheap: both already work through paths the auto-advance chain exercises (`player::pause`/`resume` and the stop+Load ritual in app.rs:824-845). Previous-item is the expensive one — starting a different item is a full engine teardown + fresh Starfish `Load` on the buffer-feed pipeline, and `next_after` deliberately DRAINS the queue rows rather than cloning them because 'a `Metadata` row carries the whole Media/Part/Stream/Role tree and this runs on the resolve worker on a 32-bit TV' (plex/timeline.rs:71-74), so retaining the predecessor row costs real heap on the ARM target.

docs/playback-navigation.md

@@ -0,0 +1,88 @@
+# Playback navigation
+
+**Previous/Next** are always part of the default control row for an episode with a neighbor
+in its existing PlayQueue; there is no setting for them. Movies, extras and a queue without
+either neighbor omit both, which leaves the three existing discs at exactly the same positions.
+
+Settings → Video & playback has one per-profile option, **Instant D-pad seeking**, Off by
+default. Off preserves reveal → target → OK for Left/Right. On makes a fresh Left/Right press
+jump immediately by the configured Skip interval when the controls are hidden. With controls
+visible, it still previews and waits for OK. Holding the D-pad in this optional
+hidden-controls path does not start a scrub.
+
+Dedicated **rewind/fast-forward** keys work independently of that option. A tap commits one
+Skip interval jump on release, without opening the controls or requiring OK. Waiting for the
+release lets a hold use the existing shared held-key mechanism without first seeking. A hold
+raises the scrubber, moves its pending target continuously and waits for OK; Back cancels it.
+
+Immediate jumps preserve pause. Fresh taps no more than 1.5 seconds apart accumulate from the
+last clamped requested target, including when reversing direction. An earlier keyframe landing
+therefore cannot erase the requested travel. After a longer gap, the next tap starts from the
+current intended playhead. Another control, pointer interaction, a held scrub or a new item
+ends the burst; a same-item seek reload preserves it. A dismissed immediate seek stays hidden
+through the first new picture; ordinary rebuffering and failures retain their diagnostic read-out.
+
+The default control row is **Previous, Next**, a wider gap, then **Subtitles, Audio, More**.
+Previous restarts at five seconds or later and shows the restart arrow. Before five seconds it
+plays the preceding queue item. Unavailable buttons are dimmed, have no pointer stop and are
+skipped by keyboard focus. Entering the row focuses Next when enabled, otherwise its first
+enabled button. Marker offers and Up Next retain their precedence over this row.
+
+## Queue continuity and maintenance
+
+The feature reuses the existing player screen, focus engine, transport widget, seek request and
+stop/resolve/start transaction. It does not copy a player renderer or change native decoding.
+Its main files are:
+
+| File under `rust-modules/` | Responsibility |
+| --- | --- |
+| `screens/src/player/seek_jump.rs` | FF/REW tap policy and optional D-pad jumps |
+| `appkit/src/player_hud/seek_jump.rs` | Short-burst requested-target accumulation |
+| `appkit/src/player_hud.rs` | One default disc row, availability, icons and shared HStack geometry |
+| `media/src/route/queue_navigation.rs` | Queue neighbors, continuation and five-second rule |
+| `plex/src/plex/session/playback_options.rs` | Independent preference types and defaults |
+| `plex/src/plex/queue_window.rs` | Read the existing PlayQueue around a target item |
+| `src/app/playback/queue_transport.rs` | Queue handoff shared with Up Next |
+
+Queue handoffs preserve the PlayQueue ID, selected item ID and known rows through the shared
+resolve environment. Creating a replacement queue from its remaining tail would lose Previous.
+Each handoff reads the existing window around the target item ID using
+`GET /playQueues/{playQueueId}` with `center`, `window`, `includeBefore`, `includeAfter` and
+`own=0`, as specified in `docs/plex-openapi.json`. Expired, unavailable or mismatched windows
+retain the known snapshot. The queue-window behavior is shared with automatic advance.
+
+The D-pad option serves remotes without dedicated FF/REW keys. It can also make frequent jumps
+through filler sections in anime more convenient while preserving the ordinary D-pad default.
+
+## Synthetic regression
+
+Use a fresh evidence directory for each run. No household account is needed:
+
+```sh
+make sim-macos
+python3 tests/fixtures/make_fixtures.py --only mockverify --out /tmp/navigation-media
+python3 tests/playback_navigation_sim.py --sim rust-modules/target-sim/debug/plxnative-sim \
+  --media /tmp/navigation-media --out /tmp/navigation-evidence
+```
+
+This exercises queue continuity, restart after five seconds, an immediate hidden-HUD FF tap,
+and visible-HUD D-pad confirmation. Add `--instant-dpad` to exercise the optional D-pad path.
+For a repeated-keyframe regression, make a copy with 12-second keyframes (24 fps):
+
+```sh
+mkdir -p /tmp/navigation-long-gop
+ffmpeg -y -i /tmp/navigation-media/mockverify-v1.mkv -t 60 -map 0 \
+  -c:v libx264 -preset ultrafast -b:v 8M -minrate 8M -maxrate 8M -bufsize 16M \
+  -x264-params nal-hrd=cbr -g 288 -keyint_min 288 -sc_threshold 0 \
+  -c:a copy -c:s copy /tmp/navigation-long-gop/mockverify-v1.mkv
+cp /tmp/navigation-media/mockverify-v2.mkv /tmp/navigation-media/mockverify-v2.eng.srt /tmp/navigation-long-gop/
+python3 tests/playback_navigation_sim.py --sim rust-modules/target-sim/debug/plxnative-sim \
+  --media /tmp/navigation-long-gop --out /tmp/navigation-burst --rapid-seeks
+```
+
+The burst regression uses FF taps with the D-pad option Off. Three requested targets advance by
+exactly ten seconds while two adjacent taps land on the same keyframe and the sequence reaches
+a later keyframe. Host tests also cover REW reversal, intervals, bounds, clock wrap, expiry,
+reset, tap versus hold, disabled focus, row spacing and title fitting. Simulator checks do not
+establish LG decoding, text rasterization or hardware video-plane behavior; use `tv-session`
+for those before shipping.

locales/be/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Імгненны пераход стрэлкамі",
+  "settings.playback.instant_dpad_seeking.copy": "Калі кіраванне схавана, Улева/Управа перамотвае на зададзены інтэрвал. Калі бачна — пацвердзіце кнопкай OK. Калі выключана, спачатку паказваецца кіраванне.",
+  "settings.playback.instant_dpad_seeking.off": "Выключана",
+  "settings.playback.instant_dpad_seeking.on": "Уключана"
+}

locales/de/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Direktsprung per Steuerkreuz",
+  "settings.playback.instant_dpad_seeking.copy": "Bei ausgeblendeten Bedienelementen springt Links/Rechts um das gewählte Intervall. Sonst bestätigt OK. Aus blendet zuerst die Bedienelemente ein.",
+  "settings.playback.instant_dpad_seeking.off": "Aus",
+  "settings.playback.instant_dpad_seeking.on": "Ein"
+}

locales/en/playback_navigation.json

@@ -0,0 +1,18 @@
+{
+  "settings.playback.instant_dpad_seeking": {
+    "value": "Instant D-pad seeking",
+    "description": "Playback setting title. Immediate D-pad jumps while controls are hidden; default Off."
+  },
+  "settings.playback.instant_dpad_seeking.copy": {
+    "value": "With controls hidden, Left/Right jumps by the skip interval. With controls visible, OK confirms. Off keeps reveal-first navigation.",
+    "description": "Explanation of optional D-pad seeking. Dedicated rewind and fast-forward work independently."
+  },
+  "settings.playback.instant_dpad_seeking.off": {
+    "value": "Off",
+    "description": "Choice for the Instant D-pad seeking setting."
+  },
+  "settings.playback.instant_dpad_seeking.on": {
+    "value": "On",
+    "description": "Choice for the Instant D-pad seeking setting."
+  }
+}

locales/es/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Salto inmediato con cruceta",
+  "settings.playback.instant_dpad_seeking.copy": "Con los controles ocultos, Izquierda/Derecha salta el intervalo elegido. Con los controles visibles, confirma con OK. Desactivado muestra primero los controles.",
+  "settings.playback.instant_dpad_seeking.off": "Desactivados",
+  "settings.playback.instant_dpad_seeking.on": "Activados"
+}

locales/fr/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Saut direct avec la croix",
+  "settings.playback.instant_dpad_seeking.copy": "Commandes masquées, Gauche/Droite saute de l’intervalle choisi. Commandes visibles, OK confirme. Désactivé, le premier appui affiche les commandes.",
+  "settings.playback.instant_dpad_seeking.off": "Désactivées",
+  "settings.playback.instant_dpad_seeking.on": "Activées"
+}

locales/hu/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Azonnali ugrás iránygombbal",
+  "settings.playback.instant_dpad_seeking.copy": "Rejtett vezérlőknél a Balra/Jobbra a beállított idővel ugrik. Látható vezérlőknél az OK erősít meg. Kikapcsolva előbb megjelennek a vezérlők.",
+  "settings.playback.instant_dpad_seeking.off": "Ki",
+  "settings.playback.instant_dpad_seeking.on": "Be"
+}

locales/it/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Salto diretto con frecce",
+  "settings.playback.instant_dpad_seeking.copy": "A controlli nascosti, Sinistra/Destra salta dell’intervallo scelto. A controlli visibili, conferma con OK. Se disattivato, mostra prima i controlli.",
+  "settings.playback.instant_dpad_seeking.off": "Disattivati",
+  "settings.playback.instant_dpad_seeking.on": "Attivati"
+}

locales/pt/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Salto direto com direcional",
+  "settings.playback.instant_dpad_seeking.copy": "Com os controlos ocultos, Esquerda/Direita salta o intervalo escolhido. Com os controlos visíveis, confirma com OK. Desativado mostra primeiro os controlos.",
+  "settings.playback.instant_dpad_seeking.off": "Desativados",
+  "settings.playback.instant_dpad_seeking.on": "Ativados"
+}

locales/ru/playback_navigation.json

@@ -0,0 +1,6 @@
+{
+  "settings.playback.instant_dpad_seeking": "Мгновенная перемотка стрелками",
+  "settings.playback.instant_dpad_seeking.copy": "При скрытом управлении стрелки перематывают на выбранный интервал. При видимом — подтвердите кнопкой OK. Если выключено, сначала показывается управление.",
+  "settings.playback.instant_dpad_seeking.off": "Выкл.",
+  "settings.playback.instant_dpad_seeking.on": "Вкл."
+}