feat: shift + arrows to seek track

js/src/features/particles/stream-view.tsx

@@ -36,6 +36,7 @@ function getReactions(particle: Particle): Record<string, string[]> | undefined
 
 const EXIT_DELAY_MS = 5000;
 const EXIT_TICK_MS = 100;
+const SEEK_DELTA_SEC = 5;
 
 type PlaybackStatus = "idle" | "playing" | "ended";
 
@@ -99,6 +100,7 @@ const STREAM_VIEW_KEYBINDINGS: KeybindingGroup[] = [
     bindings: [
       { keys: ["Hold", "Space"], description: "Pause" },
       { keys: ["Hold", "Shift"], description: "1.5× speed" },
+      { keys: ["Shift", "←", "→"], description: "Seek ±5s" },
     ],
   },
   {
@@ -269,11 +271,17 @@ function StreamViewInner({ path, streamParticle }: StreamViewProps) {
 
       switch (e.key) {
         case "ArrowRight":
+          e.preventDefault();
+          if (!e.shiftKey || !mediaRef.current?.seek(SEEK_DELTA_SEC)) next();
+          break;
         case "ArrowDown":
           e.preventDefault();
           next();
           break;
         case "ArrowLeft":
+          e.preventDefault();
+          if (!e.shiftKey || !mediaRef.current?.seek(-SEEK_DELTA_SEC)) prev();
+          break;
         case "ArrowUp":
           e.preventDefault();
           prev();