fix(clip): clip mode keeps its range, its focus and its keys through the player's own moves

- A mark on the very end seeks a moment short of it; while a clip is marked the end of the item
  neither closes the player nor steps the queue, and Plex's auto-skip waits.
- Plex: Escape and Back peel what is over the picture (info, up-next, the countdown) before the
  clip; Back under a dialog is the dialog's; no range opens while the length is unknown.
- YouTube: the focus goes back to the scissors the user can see, else the player; the panel keeps
  its name, Loop and focus when the view is maximised or restored under it.
- A typed time stays in its field until taken, then shows where it landed; unreadable stays marked
  invalid; a decimal comma is read (ui/TimecodeField, the editor's fields too).
- RangeTrack: a drag is its pointer's, a cancelled drag reports final, an adornment sits beside the
  slider, a caller-chosen focus ring (amber on the clip strip). CropFrame: a drag is its pointer's.
- The editor's remove-cut is a real button at the cut's foot; a segment's keep toggle sits over the
  cut's hit area.

frontend/src/lib/timecode.ts

@@ -13,9 +13,13 @@ export function formatTimecode(s: number, hours = false): string {
   return hours || h > 0 ? `${h}:${String(m).padStart(2, "0")}:${sec}` : `${m}:${sec}`;
 }
 
-/** A typed timecode back to seconds: `h:mm:ss.d`, `m:ss.d` or bare seconds. Null when it is not one. */
+/** A typed timecode back to seconds: `h:mm:ss.d`, `m:ss.d` or bare seconds, its decimal a point or
+ *  a comma (how a Hungarian hand writes one). Null when it is not one. */
 export function parseTimecode(v: string): number | null {
-  const parts = v.trim().split(":");
+  const parts = v
+    .trim()
+    .replace(/,(\d*)$/, ".$1")
+    .split(":");
   if (parts.length > 3 || parts.some((p) => p.trim() === "")) return null;
   let total = 0;
   for (const p of parts) {