Pierre's PatchDiff splits unified-format patches on /^---\s+\S/gm to
find file boundaries. This collides with deleted lines whose original
content starts with "-- " (e.g. SQL comments), causing
"FileDiff: Provided patch must contain exactly 1 file diff" errors.
Prepend `diff --git a/<path> b/<path>` to the header so Pierre uses
/^diff --git/gm instead, which is unambiguous.
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
3ae515839a