Any edit I make to `AGENT.md` shows up as an added table instead of a modified table

```sql
mysql> select doc_name from dolt_docs;
+----------+
| doc_name |
+----------+
| AGENT.md |
+----------+
1 row in set (0.164 sec)

mysql> select * from dolt_status;
Empty set (0.184 sec)

mysql> update dolt_docs set doc_text='test agent' where doc_name='AGENT.md';
Query OK, 1 row affected (0.170 sec)
Rows matched: 1 Changed: 1 Warnings: 0

mysql> select * from dolt_docs;
+----------+------------+
| doc_name | doc_text |
+----------+------------+
| AGENT.md | test agent |
+----------+------------+
1 row in set (0.164 sec)

mysql> select * from dolt_status;
+------------+--------+-----------+
| table_name | staged | status |
+------------+--------+-----------+
| dolt_docs | 0 | new table |
+------------+--------+-----------+
1 row in set (0.177 sec)

mysql> select * from dolt_diff_summary('main', 'WORKING');
+-----------------+---------------+-----------+-------------+---------------+
| from_table_name | to_table_name | diff_type | data_change | schema_change |
+-----------------+---------------+-----------+-------------+---------------+
| | dolt_docs | added | 1 | 1 |
+-----------------+---------------+-----------+-------------+---------------+
1 row in set (0.172 sec)
```

This also happens if I attempt to delete the AGENT.md file (which I cant - see https://github.com/dolthub/dolt/issues/9675)