bxcore: a turn's speaker, SessionUpdated's turn, the session-state messages

Co-Authored-By: ornith-1.5-35b-a3b <agent@wntrmute.dev>

crates/bxcore/tests/strict.rs

@@ -92,6 +92,10 @@ fn envelopes_reject_unknown_keys_at_every_depth() {
         "error_no_such_approval.json",
         "turn_event_approval_pending.json",
         "turn_event_tool_denied.json",
+        "turn_speaker.json",
+        "session_updated.json",
+        "session_state.json",
+        "session_state_reply.json",
     ] {
         // Envelope, msg and body: three objects. Some bodies hold more: turn_done a usage
         // object, approval_list one item, approve_result an outcome, grants_report two problems.
@@ -142,6 +146,16 @@ fn usage_log_records_reject_unknown_keys_at_every_depth() {
     assert_eq!(tried, 8);
 }
 
+#[test]
+fn speaker_log_records_reject_unknown_keys_at_every_depth() {
+    let mut tried = 0;
+    for (i, line) in fixture("records/session_speaker.jsonl").lines().enumerate() {
+        tried += check::<LogRecord>(&format!("session_speaker.jsonl:{}", i + 1), line);
+    }
+    // Five records, none holding another object.
+    assert_eq!(tried, 5);
+}
+
 #[test]
 fn grants_reject_unknown_keys_at_every_depth() {
     let grant: Grant = toml::from_str(&fixture("grant/full.toml")).unwrap();