review: memory writes from a secret session are not written to Honcho

The journal now records each call's class (absent on the owner's undo and on
older lines, which still read). The mirror turns everything a secret write
would conclude or send to the fleet into one Skip, after its deletions, which
still go; a note whose own header says secret is skipped the same way.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

crates/memoryd/tests/honcho_mirror.rs

@@ -57,6 +57,7 @@ fn record(id: &str, action: &str, file: Option<&str>, before: &[&str], after: &[
         untrusted: false,
         flag: None,
         undoes: None,
+        class: None,
     }
 }