[v/25.3] manage/k8s: document decommission timing (--decommission-wait-interval)

[david-yu]

Backport of #1761 to v/25.3.

Adds the "Tune automatic decommission timing" section to the Kubernetes decommission page:

• --decommission-wait-interval (Operator, via additionalCmdFlags) — the Decommission controller's requeue interval (RequeueAfter).
• decommissionRequeueTimeout / decommissionAfter (Helm sidecar).
• A TIP cross-reference from the Operator install step, the shell-correct --set "additionalCmdFlags={...}" quoting, and guidance for adjusting the intervals.

Backport note

The Operator-example rewrite from #1761 (the "do not add sideCars.brokerDecommissioner here" paragraph + <1> callout) is main-only and intentionally omitted here: v/25.3's Operator example uses the version-appropriate brokerDecommissioner sidecar, so backporting that paragraph would contradict the example on this branch.

Verified that all cross-references resolve on v/25.3: <<decommission-timing>>, <<Automated>>, and reference:{cluster,tunable}-properties.adoc#... (the latter via the existing properties/cluster-properties.adoc page-aliases, already used elsewhere on this branch).

🤖 Generated with Claude Code

[netlify]

✅ Deploy Preview for redpanda-docs-preview ready!

Name	Link
🔨 Latest commit	d58d729
🔍 Latest deploy log	https://app.netlify.com/projects/redpanda-docs-preview/deploys/6a3c1b565816a30008d882da
😎 Deploy Preview	https://deploy-preview-1763--redpanda-docs-preview.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 34be689a-10a8-4a97-bef6-f3a1dc1d44f6

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch dyu/backport-1761-decommission-v25.3

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[micheleRP]

Backport review — LGTM

Verified this backport of #1761 against `v/25.3`; it's technically correct and version-appropriate:

• `--decommission-wait-interval` is a real operator flag (`redpanda-operator` `operator/cmd/run/run.go`, default `8s`), valid for the operator version pinned on this branch (`v2.3.8-24.3.6`). ✓
• Cross-references resolve on `v/25.3`: `<>`, `<>` (`[[Automated]]` present), and the `reference:{cluster,tunable}-properties.adoc#...` xrefs via the existing `page-aliases` on `properties/cluster-properties.adoc`. ✓
• Correctly omits the main-only Operator-example rewrite, since `v/25.3`'s Operator example uses the `brokerDecommissioner` sidecar. ✓
• Shell-quoting fix (`--set "additionalCmdFlags={--additional-controllers=decommission}"`) is correct.

One note (no action needed): the second commit bundles a `netlify.toml` CI fix (`NODE_VERSION = "20"`) to unblock the preview build on this branch — unrelated to the content but justified and self-contained.