Write the name in lowercase where people see it

The brand is lowercase inbuxa. This changes what the app calls itself by
default, the wordmark's accessible name, the sign-in card's version line, the
installed app's name in the manifest, and the four translated strings that
name the console or the mail server.

Those four are source strings, so their catalog keys changed with them in all
nine languages; the translations keep their text with the name corrected. No
key was left behind, and no language falls back on more strings than before:
1643/1662 translated, 19 falling back, in each of the nine, unchanged.

Code identifiers, capability URNs, env var names and comments are untouched.

server/src/config.ts

@@ -278,7 +278,7 @@ if (oauthClientSecret && !publicUrl) {
 
 export const config = {
   isProd,
-  appName: env("APP_NAME", "INBUXA"),
+  appName: env("APP_NAME", "inbuxa"),
   settingsPolicy: readSettingsPolicy(),
   /**
    * What this build calls itself: `2.16.57`. Set by the image build from