0.2.62 - Roll back the custom playback engine

0.2.61 shipped the groundwork for Memby playing video itself and caused
playback problems in the field, so it is withdrawn. This is 0.2.60's code
released as 0.2.62: Android refuses an APK whose versionCode went
backwards, so a set already on 0.2.61 (20061) could not install a 0.2.60
build (20060).

The 0.2.61 work is parked on parked/0.2.61 and tagged broken-0.2.61.

Also corrects the changelog headings the reset left behind: the top block
was labelled 0.2.59 while holding 0.2.60's notes, and 0.2.59's own two
entries were folded into it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app/build.gradle.kts

@@ -42,7 +42,7 @@ val projectNoticeText =
 
 // A release workflow can derive the app version from its Git tag without editing the
 // source tree. Local builds keep using the checked-in default.
-val defaultVersionName = "0.2.60"
+val defaultVersionName = "0.2.62"
 val membyVersionName: String =
     (project.findProperty("memby.versionName") as String?)
         ?.trim()