fix: remove orphaned json/session_messages.json with no backing table definition

json/session_messages.json

@@ -1,23 +0,0 @@
-{
-    "tblname": "session_messages",
-    "title": "Session Messages",
-    "params": {
-        "sortby": ["created_at asc"],
-        "confidential_fields": [],
-        "browserfields": {
-            "exclouded": ["id", "session_id", "user_id", "updated_at"],
-            "alters": {
-                "role": {
-                    "uitype": "code",
-                    "data": [
-                        {"value": "user", "text": "User"},
-                        {"value": "assistant", "text": "Assistant"},
-                        {"value": "system", "text": "System"}
-                    ]
-                }
-            }
-        },
-        "editexclouded": ["id", "session_id", "user_id", "created_at", "updated_at"],
-        "subtables": []
-    }
-}