The proxy IP check was never enforced: ServiceProxyAuth read config
key 'proxy_check' but the property is registered as 'check_proxy',
so the lookup always returned the default empty string and the
else-branch set $sProxyRequest = true unconditionally.
The BOOL property also had SetEncrypted(), which caused getDecrypted()
to call DecryptFromJSON() on a literal bool and fail with
"DecryptFromJSON() invalid $data", so the admin UI never reflected
the saved value. BOOLs are stored as plain bools in JSON; switch to
Get() and drop SetEncrypted() on the property.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
