[k8s] Promote a selection of container and k8s memory metrics to release_candidate

[ChrsMark]

Fixes #3882

After the evaluation described at #3882 (comment) I suggest we promote these metrics to release_candidate.

These have been in use from the https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/receiver/kubeletstatsreceiver/documentation.md for some time now without issues.

Changes

Please provide a brief description of the changes here.

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Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Links to prototypes or existing instrumentations (when adding or changing conventions)
• Disclose AI usage, see OTel GenAI policy:
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• I have the experience and knowledge necessary to understand, review, and validate all content in this PR.¹

Footnotes

1. Yes, I can answer maintainer questions about the content of this PR without using AI. ↩

[TylerHelmuth]

🎉

[dashpole]

Looks like some of these are the wrong instrument type.

[Copilot]

Pull request overview

This PR promotes a specific set of Kubernetes and container memory metrics from development to release_candidate, reflecting their maturity and established usage in existing instrumentation (per issue #3882).

Changes:

• Promotes *.memory.{usage,available,rss,working_set} metrics for container, k8s.pod, and k8s.node to release_candidate.
• Expands/clarifies metric notes to describe semantics and derivation from Kubelet stats API (and cAdvisor for container metrics).
• Adds a changelog entry documenting the promotion.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
model/k8s/metrics.yaml	Promotes selected k8s pod/node memory metrics to RC and clarifies *.memory.usage derivation/semantics.
model/container/metrics.yaml	Promotes selected container memory metrics to RC and expands notes (including cAdvisor + Kubelet derivation).
docs/system/k8s-metrics.md	Regenerates published k8s metrics docs to reflect RC status and updated notes.
docs/system/container-metrics.md	Regenerates published container metrics docs to reflect RC status and updated notes.
.chloggen/rc_mem_metrics.yaml	Adds release note entry for the RC promotion.

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Status last refreshed: 2026-07-25 18:54:46 UTC.

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