hive-agent: correct doc comments that describe sentinel files, session flags and outcomes the code no longer has

hive-agent/src/boot_announce.rs

@@ -46,8 +46,8 @@ pub fn announce(label: &str, todos: &Todos, wake: &Notify) {
     let summary = format!(
         "You were just (re)started. If you were mid-task, check \
          `/agents/{label}/state/` for your notes and pick up where you left \
-         off — claude's `--continue` session is intact, so prior context is \
-         still in your window."
+         off — your claude session (resumed by title) is intact, so prior \
+         context is still in your window."
     );
     match todos.upsert(SUBSYSTEM, Some(KEY), &summary, None, true) {
         Ok((_, true)) => wake.notify_one(),