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/src/notes.rs

@@ -37,7 +37,8 @@ pub fn minute(time: Timestamp) -> String {
     format!("{}Z", s.get(..16).unwrap_or(&s))
 }
 
-fn class_name(class: DataClass) -> &'static str {
+/// A class as the notes and the journal spell it, the same as on the wire.
+pub fn class_name(class: DataClass) -> &'static str {
     match class {
         DataClass::Public => "public",
         DataClass::Private => "private",