[v25.3.x] cluster/health: use kafka high watermark in partition_status

[vbotbuildovich]

Backport #30873 to branch v25.3.x. This issue was created as a placeholder because the original PR's commit(s) could not be automatically cherry-picked.
Here are the commands to execute:

git checkout v25.3.x
git checkout -b manual-backport-30873-v25.3.x-924
git cherry-pick -x f4352ada31

git push origin manual-backport-30873-v25.3.x-924
gh pr create \
  --title "[v25.3.x] cluster/health: use kafka high watermark in partition_status" \
  --base "v25.3.x" \
  --label "kind/backport" \
  --head "manual-backport-30873-v25.3.x-924" \
  --draft \
  --repo "redpanda-data/redpanda" \
  --milestone "v25.3.x-next" \
  --body "Backport of PR https://github.com/redpanda-data/redpanda/pull/30873 "