fix(scripts): chunk Phase C deletes to dodge SQLite param cap

DELETE ... WHERE itemID IN (?,?,...) with 33k+ host parameters
trips SQLITE_LIMIT_VARIABLE_NUMBER (default 32766 on modern builds,
999 on older). Batch by 500 so the cleanup runs to completion
regardless of build limits.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/migrate_comment_md_to_notes.py

@@ -196,14 +196,19 @@ def phase_c_cleanup() -> dict[str, int]:
         item_ids_to_delete.append(item_id)
 
     if item_ids_to_delete:
-        placeholders = ",".join("?" * len(item_ids_to_delete))
+        # SQLite caps host parameters per statement (default 32766 on 3.32+,
+        # 999 on older builds). 33k+ IDs at once trips it — chunk to be safe.
+        BATCH = 500
+        for i in range(0, len(item_ids_to_delete), BATCH):
+            chunk = item_ids_to_delete[i : i + BATCH]
+            placeholders = ",".join("?" * len(chunk))
             zot_con.execute(
                 f"DELETE FROM itemAttachments WHERE itemID IN ({placeholders})",
-            item_ids_to_delete,
+                chunk,
             )
             zot_con.execute(
                 f"DELETE FROM items WHERE itemID IN ({placeholders})",
-            item_ids_to_delete,
+                chunk,
             )
         stats["zot_rows_deleted"] = len(item_ids_to_delete)
     zot_con.commit()