Brand the webmail INBUXA: name, mark and wordmark

INBUXA is a product suite and ihasmail an independent product, so INBUXA's
webmail says INBUXA: the sign-in page, header, page title, installed-app name
and About page. The wordmark is drawn in the current text color. ihasmail's
version and AGPL source line stay as its credit. Two new strings, in all nine
catalogues; three Stalwart-only ones are no longer used.

web/src/lib/brand.ts

@@ -10,4 +10,6 @@
  * One constant rather than the string written out at each of them, because
  * three copies of a default is how two of them end up stale.
  */
-export const DEFAULT_APP_NAME = "ihasmail";
+// ihasmail-inbuxa: INBUXA's webmail goes by INBUXA, so it can't be taken for
+// public ihasmail. APP_NAME still names a deployment whatever it likes.
+export const DEFAULT_APP_NAME = "INBUXA";