Deprecated:
Client diff. Pending review uses show_pending_diff.
Show inline unified diff from a caller-owned OLLMfiles.Diff.Differ.
Builds interleaved equal / removed / added rows. Green and red come from buffer tags; removed lines are non-editable but selectable/copyable. The gutter shows the new file's line numbers. Removed lines are blank. Does not write disk. Caller restores with clear_diff.
| differ |
already constructed (text1 = V_backup, text2 = V_disk) |