rpk: add high disk usage report on 'cluster health'

[r-vasquez]

This was introduced in 5b5286f and already released in 25.3.5

Solves INC-1051

Example

$ rpk cluster health
CLUSTER HEALTH OVERVIEW
=======================
Healthy:                          false
Unhealthy reasons:                [high_disk_usage_nodes]
Controller ID:                    0
All nodes:                        [0]
Nodes down:                       []
Nodes in recovery mode:           []
Nodes with high disk usage:       [0]
Leaderless partitions (0):        []
Under-replicated partitions (0):  []
Cluster UUID:                     1e0e7ba3-b3ca-4e6b-a8ca-453170d6b0af

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v25.3.x
• v25.2.x
• v25.1.x

Release Notes

Features

• rpk cluster health: high_disk_usage_nodes is now reported.

[Copilot]

Pull request overview

This PR adds support for displaying nodes with high disk usage in the rpk cluster health command output. The feature was previously added in commit 5b5286f and released in version 25.3.5, and this change surfaces that information in the CLI.

Changes:

• Added HighDiskUsageNodes field to the health response structure
• Updated the health overview output to display nodes with high disk usage
• Updated protobuf and dependency versions to support the new field

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated no comments.

File	Description
src/go/rpk/pkg/cli/cluster/health.go	Added HighDiskUsageNodes field to struct and print logic to display nodes with high disk usage
src/go/rpk/go.mod	Updated dependencies including protobuf definitions and rpadmin library to versions that support high disk usage reporting
buf.gen.yaml	Updated core module reference to newer version containing high disk usage definitions

[vbotbuildovich]

CI test results

test results on build#80350

test_class	test_method	test_arguments	test_kind	job_url	test_status	passed	reason	test_history
NodesDecommissioningTest	test_decommission_status	null	integration	https://buildkite.com/redpanda/redpanda/builds/80350#019c353f-ded9-4343-b788-9fdb6adec6ad	FLAKY	10/11	Test PASSES after retries.No significant increase in flaky rate(baseline=0.0484, p0=1.0000, reject_threshold=0.0100. adj_baseline=0.1382, p1=0.2260, trust_threshold=0.5000)	https://redpanda.metabaseapp.com/dashboard/87-tests?tab=142-dt-individual-test-history&test_class=NodesDecommissioningTest&test_method=test_decommission_status

[vbotbuildovich]

/backport v25.3.x

[vbotbuildovich]

Failed to create a backport PR to v25.3.x branch. I tried:

git remote add upstream https://github.com/redpanda-data/redpanda.git
git fetch --all
git checkout -b backport-pr-29480-v25.3.x-647 remotes/upstream/v25.3.x
git cherry-pick -x 9b48d17457

Workflow run logs.

[r-vasquez]

/backport v25.3.x

[vbotbuildovich]

Failed to create a backport PR to v25.3.x branch. I tried:

git remote add upstream https://github.com/redpanda-data/redpanda.git
git fetch --all
git checkout -b backport-pr-29480-v25.3.x-829 remotes/upstream/v25.3.x
git cherry-pick -x 9b48d17457

Workflow run logs.