About box shows only the newest 5 releases (screen-reader crash fix)

The About box's release notes had accumulated the ENTIRE version history back to v1.0 —
~70 KB in a single TextBox — and reading a control value that size crashes some screen
readers (user reports, 2026-08-11). The box now displays only the newest five version
blocks via a pure trim (TrimToLastVersions), ending with a plain pointer to the full
history on the GitHub releases page. The full constant stays in source as the archive.

Gate: new step pins the trim logic on synthetic notes AND the real shipped text (exactly
5 versions, size well under the crashing range — 5,516 chars vs ~70,000) so the crash
can't quietly return as releases accumulate. 73/73. Readme About section updated + MANUAL
regenerated; 5.8 notes mention the change.

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

MANUAL.md

@@ -1175,7 +1175,7 @@ A step-by-step record of every update is kept in a file called `updater.log` in
 
 ### The About dialog and release notes
 
-To see which version you're on without checking for updates, open **Help → About RemSound** (Alt+H, A). The dialog shows the version number and the release notes for the version you're running, in a scrollable read-only box. Close (or Esc) dismisses it.
+To see which version you're on without checking for updates, open **Help → About RemSound** (Alt+H, A). The dialog shows the version number and the release notes for the newest five versions, in a scrollable read-only box — newest first, so what just changed is right at the top. Notes for every older version live on the RemSound releases page on GitHub. Close (or Esc) dismisses it.
 
 ## 21. Recording to a file