chore: bump VERSION 0.62.1 + release notes (R12 S4a PlexPlayer refactor)

VERSION

@@ -1 +1 @@
-0.62.0
+0.62.1

frontend/src/lib/releaseNotes.ts

@@ -14,6 +14,13 @@ export interface ReleaseEntry {
 }
 
 export const RELEASE_NOTES: ReleaseEntry[] = [
+  {
+    version: "0.62.1",
+    date: "2026-08-12",
+    chores: [
+      "Internal refactor of the Plex player: split the large player component into focused, self-contained hooks. No change to how the player looks or behaves.",
+    ],
+  },
   {
     version: "0.62.0",
     date: "2026-08-11",