The patch builder works in patch-line-index space, which the patch
explorer can supply directly from its parsed-patch state. The focused
main view can't: it only knows a selection as diff-line metadata
identities (file line number + deletion?), and those indices differ
between the raw diff and however a pager renders it.
Add the conversion at the boundary so the main view stays in identity
space: PatchLineIndicesForLines maps identities to indices (for
toggling) and IncludedLineIdentities reports the included change lines
as identities (for the inclusion gutter to match rendered rows against).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
