Versioning: INBUXA's own dated version, with the Stalwart base shown

inbuxa --version, the banner, startup events, OpenTelemetry and the JMAP
implementation string read "2026.9.18 (Stalwart 0.16.22)". The base comes
from Cargo, which keeps following upstream so version bumps merge cleanly.
Received headers and IMAP ID carry the INBUXA version.

crates/imap/src/op/capability.rs

@@ -70,7 +70,9 @@ impl<T: SessionStream> Session<T> {
                     concat!(
                         "* ID (\"name\" \"",
                         types::brand!(),
-                        "\" \"version\" \"1.0.0\" \"vendor\" \"",
+                        "\" \"version\" \"",
+                        types::brand_version!(),
+                        "\" \"vendor\" \"",
                         types::brand!(),
                         "\" \"support-url\" \"",
                         types::brand_url!(),