Gengchou v2.2.4

Gengchou v2.2.4

v2.2.4 is the one-time bridge from the former internal identity to Gengchou.
It is not a WinGet release.

What changes

• Move settings and a valid, fresh usage cache to %APPDATA%\Gengchou.
• Start a new diagnostic log and updater workspace under
  %LOCALAPPDATA%\Gengchou.
• Move the Start with Windows value to Gengchou after verifying that it
  belongs to the running executable.
• Use Gengchou window classes and relaunch variables. During this bridge only,
  the app holds both the old and new mutexes so v2.2.3 and v2.2.4 cannot run
  together.
• Accept the v2.2.3 updater's old ready-marker protocol on entry. Updates
  started by v2.2.4 use only the new Gengchou protocol.
• Pause all later update checks until the migration reaches complete, so a
  future v2.3.0 cannot be installed before the required second start.

Required one-time restart

1. Update to v2.2.4 and confirm that the app is running normally.
2. Exit Gengchou, then start gengchou.exe once more.
3. Place verify-v2.2.4-migration.ps1 beside this release's SHA256SUMS, then
   run it with -RequireMigratedSource -RequireOfficialHash. Continue to
   v2.3.0 only after it reports PASS.

A clean v2.2.4 installation with no earlier settings should omit
-RequireMigratedSource and still require the official hash.

The first launch copies and verifies user data but does not delete its source.
The second launch removes only known old files owned by this project. Data from
the original CodeZeno application is never deleted. If an owned old directory
contains an unknown file or a reparse point, monitoring remains available, but
cleanup stays pending and updates remain disabled. The old diagnostic log is
not copied.

Keep this release available as the supported bridge for installations on
v2.2.3 or earlier. Keeping it downloadable is not enough: v2.3.0 must not be
published until every supported pre-v2.2.4 installation has run v2.2.4 twice
and passed the verifier. A clean installation without old settings is the only
exception.