Call the app by its name in every sentence that names it (#406)

APP_NAME renames an instance, but only the sign-in page, the title bar and
a few headings used it. Two dozen sentences wrote "ihasmail" into
themselves, so a renamed instance still told people to keep an ihasmail
tab open and offered to open mail links "in ihasmail".

Those sentences now take the name as {app}, which also lets a translator
put it where their language wants it. brand.ts grew useAppName() for
components and currentAppName() for the few places that build strings
outside React.

Left as they are: the Files folder "ihasmail", the Sieve script
"ihasmail" and ihasmail.org. Those name things a person can go and look
at, and renaming them would rename real data.

All nine catalogues keep their translations: the name inside each one
became the placeholder. Three of the strings had no translation before
and still fall back to English.

A test walks the sources and the catalogues so a new sentence can't
hard-code the name again.

web/src/lib/sw/swFacts.ts

@@ -16,6 +16,7 @@
  * was installed, which is the same condition background notifications already
  * carry — a push subscription has to be renewed from a tab too.
  */
+import { currentAppName } from "@/lib/brand";
 import { withBase } from "../basePath";
 import { SW_CACHE_NAME } from "./swCache";
 import { t } from "../i18n";
@@ -57,7 +58,7 @@ export async function publishWorkerFacts(accountId: string | null, archiveId: st
       noSubject: t("(no subject)"),
       archive: t("Archive"),
       markRead: t("Mark as read"),
-      failed: t("Could not do that — open ihasmail and try again"),
+      failed: t("Could not do that — open {app} and try again", { app: currentAppName() }),
     },
   };
   try {