Summary

Fixes #11670

This PR updates the chart installation logic to only apply the default linux OS restriction if the chart originates from an official Rancher repository. This prevents external charts without catalog.cattle.io/permits-os annotations from being incorrectly blocked from installation on Windows nodes.

Occurred changes and/or fixed issues

• Modified the repository identification logic to accurately detect Rancher repositories, specifically adding support for airgapped environments where the registry URL does not end in .rancher.io.
• Updated compatibleVersionsFor to only fall back to linux when evaluating permitted OS if the chart is from an official Rancher repository.
• Updated windowsIncompatible logic in the chart install page and chart mixin to use the new shared isRancherRepo helper and only apply the fallback to official Rancher repositories.

Technical notes summary

• Created a shared isRancherRepo(repo, chart) helper function in shell/store/catalog.js to centralize the logic for detecting official Rancher repositories.
• The isRancherRepo helper checks if the repository is natively identified as a Rancher source or if it's an airgapped repository (specifically, a ClusterRepo named rancher-charts or rancher-partner-charts). By verifying CATALOG.CLUSTER_REPO, we ensure standard users cannot spoof official repositories within namespace-scoped repos.
• Added comprehensive unit tests for isRancherRepo and compatibleVersionsFor to ensure correct behavior across different repository types and OS constraints.

Areas or cases that should be tested

• External charts on Windows clusters: Verify that installing a 3rd-party chart (not from a Rancher repo) without the catalog.cattle.io/permits-os annotation is permitted on clusters with Windows nodes and does not show the "Windows Incompatible" warning.
• Rancher charts on Windows clusters: Verify that official Rancher charts without the OS annotation are still restricted to Linux and correctly show the "Windows Incompatible" warning on Windows clusters.
• Airgap environments: Verify that in an airgapped setup where the rancher-charts repository URL is modified to an internal registry, Rancher charts are still correctly identified as official and default to Linux if no OS annotation is present.

Areas which could experience regressions

• Chart installation and version selection for both official Rancher charts and third-party charts.
• Display of "Windows Incompatible" and "Linux Only" warnings in the Apps & Marketplace catalog and installation workflows.
• Repository parsing and identification in airgapped environments.

Screenshot/Video

I've mocked the workerOs getter in order to test this:
shell/models/management.cattle.io.cluster.js:

  get workerOSs() {
    return ['windows', 'linux'];
  }

then I've added the permit os annotation catalog.cattle.io/permits-os to my dummy chart's different versions to test different cases:
version 0.1.0 > no annotation
version 0.2.0 > catalog.cattle.io/permits-os: "linux"
version 0.3.0 > catalog.cattle.io/permits-os: "linux,windows"

here's my repo's URL https://momesgin.github.io/mo-charts/ in case you need to use it.

now let's compare before an after based on these mocked data,
BEFORE:
version 0.1.0

version 0.2.0:

version 0.3.0:

chart install/edit page after installation:

AFTER:
version 0.1.0

version 0.2.0:

version 0.3.0:

chart install/edit page after installation:

Note: For the linux only charts from Rancher repos we keep the behaviour as before.

Checklist

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