Pass merge.conflictStyle=zdiff3 on the git merge invocation so every
conflicted file gets base-aware (|||||||) markers from the start, not
just the ones runMergiraf happens to touch. Benefits:
- Mergiraf always has a base section to work from, so its structural
heuristics apply uniformly.
- Remaining manual conflicts show both sides relative to the common
ancestor, which is dramatically easier to resolve than a 2-way marker.
Since the working tree already carries diff3 markers after the merge,
drop the per-file `git checkout --conflict=diff3` in runMergiraf.
Uses 'git merge-base --is-ancestor' per tag (parallelized) to mark
upstream versions reachable from HEAD with a '✓ merged' annotation.
Kilo's own package version no longer tracks upstream, so semver
comparison isn't reliable; the ancestor check is the source of truth
and handles non-linear merge history correctly.
Append --tags --force flags to the git fetch upstream command so that
upstream tag references are always updated and locally diverged tags
are overwritten to match the remote state.
Mark IJbema