RFC: Support filtering on a predefined list of namespaces

[bjuraga-itandcare]

Summary

Add support for filtering resources using predefined lists of namespaces, allowing users to quickly switch between reusable namespace groupings.

Motivation

Current namespace selection is manual and sticky, but not reusable. In multi-team or large-cluster environments, repeatedly selecting the same namespaces is inefficient and error-prone.

Proposal

Introduce Namespace Lists:

• User-defined, named collections of namespaces
• Selectable as a single filter across the UI
• Applied equivalently to selecting all included namespaces
• Persisted in user configuration

UI

• Extend namespace selector with:
  • List selection
  • Create/edit/delete lists
• Maintain existing behavior for individual namespaces

Use Cases

• Team-based grouping (e.g., platform team, feature teams)
• Environment grouping (e.g., dev, staging, prod)
• Fast context switching between logical namespace sets

Non-Goals

• Changes to Kubernetes filtering mechanisms
• RBAC integration
• Replacing existing namespace selection

Future Enhancements

• Shared/team-wide lists
• Dynamic lists (labels, patterns)
• Import/export support

Conclusion

Namespace Lists build on existing functionality to significantly improve usability in multi-namespace environments with minimal complexity.