fix: in-memory transcript blocks empty-session prune

CI caught tests/cli/test_cli_new_session.py asserting that /new keeps
the old session row when conversation history exists in memory. The
live transcript is authoritative: a session whose messages haven't
flushed to the DB yet (or whose flush failed) must not be pruned.
Guard _discard_session_if_empty on self.conversation_history and pin
the behavior with a test.

cli.py

@@ -5833,6 +5833,12 @@ class HermesCLI(CLIAgentSetupMixin, CLICommandsMixin):
         """
         if not self._session_db or not session_id:
             return False
+        # In-memory transcript is authoritative: if this CLI object holds
+        # conversation messages (flushed to the DB or not), the session is
+        # not empty. Protects against pruning a real conversation whose DB
+        # flush failed or hasn't happened yet.
+        if getattr(self, "conversation_history", None):
+            return False
         try:
             from hermes_constants import get_hermes_home as _ghh
             return self._session_db.delete_session_if_empty(

tests/test_empty_session_hygiene.py

@@ -113,6 +113,7 @@ class TestCLIDiscardSessionIfEmpty:
 
         cli = HermesCLI.__new__(HermesCLI)
         cli._session_db = db
+        cli.conversation_history = []
         return cli
 
     def test_discards_empty(self, db):
@@ -146,3 +147,15 @@ class TestCLIDiscardSessionIfEmpty:
 
         cli = self._make_cli(Boom())
         assert cli._discard_session_if_empty("x") is False
+
+    def test_in_memory_history_blocks_prune(self, db):
+        """The live transcript is authoritative: even if the DB row has no
+        flushed messages yet, a CLI holding conversation history must not
+        prune the session (covers flush-failed / not-yet-flushed turns)."""
+        db.create_session(session_id="unflushed", source="cli", model="test")
+        db.end_session("unflushed", "new_session")
+
+        cli = self._make_cli(db)
+        cli.conversation_history = [{"role": "user", "content": "hello"}]
+        assert cli._discard_session_if_empty("unflushed") is False
+        assert db.get_session("unflushed") is not None