```python
# /// intent
# goal   = "Print the sum of the size field over all valid rows in data/rows.jsonl."
# reads  = ["data/rows.jsonl"]
# writes = []
# output = "printed"
# ///

import json
from pathlib import Path

def main():
    text = Path("data/rows.jsonl").read_text()
    total = 0
    for line in text.splitlines():
        try:
            row = json.loads(line)
        except json.JSONDecodeError:
            continue
        total += row.get("size", 0)
    print(total)

main()
```