Function matchListByText

Pairs each parsed item with at most one existing item by text similarity.

Two passes:

1. Exact text match — handles unchanged items and pure reorders.
2. Fuzzy match (Sørensen–Dice on character bigrams) on the residual — handles typo-level edits.

Both passes respect the optional getGroup constraint and are greedy: each existing item can match at most one parsed item.

Use case: round-tripping a structured markdown form back to a database upsert without losing row ids when the user edits text in place.