parse_json unconditionally replaced every single quote with a double
quote (`.replace("'", '"')`) before calling json.loads. This corrupted
any valid JSON string value containing an apostrophe, e.g. a person's
surname "Sarah O'Brien" became "Sarah O"Brien", causing the parse to
fail with "Invalid JSON" and the whole import to be rejected.
Parse strict JSON first so well-formed payloads (including apostrophes
in string values) import correctly, and only fall back to the lenient
single-quote replacement for Python-dict-style payloads that are not
valid JSON on their own.
Adds regression tests covering an apostrophe-bearing JSON value and the
retained single-quoted fallback.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
