Merge Request with conflict sometines does not show the conflict in the diff (missing `conflict_type`)
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## Problem
Sometimes the server responds with `has_conflicts: true` but `conflict_type: null`. This prevents us from being able to accurately display the conflict state.
When both fields are present but in this inconsistent state, the UI cannot determine what type of conflict exists, making it impossible to show users the appropriate conflict information or resolution options.
Example: https://gitlab.com/gitlab-com/content-sites/handbook/-/merge_requests/17166#note_2948044618
## Proposal
Always provide a `conflict_type` when `has_conflict` is true.
issue