fix(player): a step onto an unplayable video carries on the way it went

Previous onto an embed-blocked or removed video skipped forward again (the
auto-advance direction), straight back to the item just left. The player now
remembers the direction of the step that reached the item and the videos
YouTube refused this session: an error carries on that way, Previous / Next
pass over known-dead items without loading them, and go dark when only those
are left. A step of your own skips with auto-advance off too.

frontend/src/lib/playerModalHooks.progress.dom.test.tsx

@@ -76,14 +76,13 @@ function mountPlayer(qc: QueryClient, sessionPos: Map<string, number>) {
       mountRef: { current: mount },
       playerRef: createRef<YTPlayer>() as RefObject<YTPlayer | null>,
       currentIdRef: { current: VID },
-      navRef: { current: { queue: undefined, index: 0 } },
-      modeRef: { current: { autoMode: "off", loopMode: "off" } },
       setWatched: () => {},
       setPlayerError: () => {},
       setLiveData: () => {},
       reapplyStored: () => {},
       reclaimFocus: () => {},
       advanceOnEnd: () => {},
+      skipUnplayable: () => {},
       sessionPosRef: { current: sessionPos },
       qc,
     }),