Fork Stalwart WebUI v1.0.11 as INBUXA Admin

- One edition: whatever edition the server reports, nothing is hidden or
  disabled as Enterprise-only (accountStore.setAccountInfo).
- INBUXA branding: name, logo (mark plus a text-colored wordmark), favicon,
  page titles, setup wizard text, and ihasmail's palette in light and dark.
- Two-factor setup names INBUXA as the issuer and drops the image parameter
  that made authenticator apps fetch a logo from a third-party site.
- Runs apart from the server: the server address can be set at deploy time
  with <meta name="api-base-url">, and OAuth endpoints the server returns as
  relative paths are resolved against the server's address, not the page's.
  Verified end to end against a separate inbuxa-server.
- Upstream's release workflow moved to .github-upstream so it never runs.

Upstream's history contains no Enterprise-only code, so this is an ordinary
fork. upstream is a fetch-only remote.

src/components/layout/TopBar.tsx

@@ -88,7 +88,7 @@ export function TopBar() {
             </Link>
           </TooltipTrigger>
           <TooltipContent side="bottom">
-            {t('version.label', 'Stalwart WebUI v{{version}}', { version: __APP_VERSION__ })}
+            {t('version.label', 'INBUXA Admin v{{version}}', { version: __APP_VERSION__ })}
           </TooltipContent>
         </Tooltip>
       </TooltipProvider>