Rebrand to INBUXA: product name, protocol greetings, sign-in page, calendar templates, logos, README

One branding module (types::brand!) supplies the name to every protocol
greeting, the HTTP realm, the startup banner, Received headers, the
user agent, the IMAP ID response and calendar PRODIDs. The sign-in and
calendar pages take ihasmail's palette and font and the INBUXA logo, and
calendar emails embed the INBUXA lockup. Default calendar and address book
names follow. Protocol identifiers (urn:stalwart:jmap, vnd.stalwart Sieve
extensions) and upstream copyright notices are unchanged.

crates/common/src/manager/restore.rs

@@ -52,9 +52,9 @@ impl Core {
         if !conflicts.is_empty() {
             eprintln!(
                 "Cannot import: the target database already contains data in the key ranges being \
-                 imported. This usually means Stalwart was started before the import ran, which \
+                 imported. This usually means the server was started before the import ran, which \
                  can create duplicate entries. Import into a fresh, empty database and do not \
-                 start Stalwart before importing. Conflicting dumps:"
+                 start the server before importing. Conflicting dumps:"
             );
             for path in conflicts {
                 eprintln!("  {}", path.display());