fix: offset-without-limit was silently ignored in get_messages

Review finding: get_messages(offset=N) with no limit dropped the OFFSET
entirely. SQLite requires a LIMIT clause for OFFSET, so emit LIMIT -1
(unbounded) when only offset is given. Regression test added.

hermes_state.py

@@ -3764,6 +3764,8 @@ class SessionDB:
         When ``limit`` is provided, returns at most ``limit`` messages
         starting from ``offset`` (0-based, in insertion order). Enables
         pagination for the API endpoint to avoid loading entire transcripts.
+        ``offset`` alone (without ``limit``) also pages — SQLite requires a
+        LIMIT clause for OFFSET, so it's emitted as ``LIMIT -1`` (unbounded).
         """
         active_clause = "" if include_inactive else " AND active = 1"
         sql = (
@@ -3771,9 +3773,10 @@ class SessionDB:
             f"{active_clause} ORDER BY id"
         )
         params: list = [session_id]
-        if limit is not None:
+        if limit is not None or offset:
+            # SQLite's OFFSET requires LIMIT; -1 means "no limit".
             sql += " LIMIT ? OFFSET ?"
-            params.extend([limit, offset])
+            params.extend([-1 if limit is None else limit, offset])
         with self._lock:
             cursor = self._conn.execute(sql, params)
             rows = cursor.fetchall()

tests/test_hermes_state.py

@@ -5506,3 +5506,10 @@ class TestGetMessagesPagination:
         db._conn.commit()
         page = db.get_messages("s1", limit=3, offset=0)
         assert [m["content"] for m in page] == ["msg-2", "msg-3", "msg-4"]
+
+    def test_offset_without_limit_pages(self, db):
+        """offset alone must not be silently ignored (review finding):
+        SQLite needs LIMIT for OFFSET, emitted as LIMIT -1."""
+        self._seed(db, n=5)
+        rows = db.get_messages("s1", offset=3)
+        assert [m["content"] for m in rows] == ["msg-3", "msg-4"]