Platform composition support beyond Crossplane (kro)

[monadic]

Motivation

The Crossplane work established a reusable pattern for explaining generated resources:

• XR-first abstraction
• deterministic lineage resolver
• graceful partial lineage
• shared consumption by trace, tree, and map

Other composition engines (notably kro) have the same characteristics:

• resources generated from higher-level abstractions
• metadata that may be incomplete
• misleading "unmanaged" classifications today

Scope

• Add support for kro (or similar composition engines) by:
  • implementing a resolver that identifies the platform root (kro equivalent of XR)
  • extracting lineage using kro metadata (annotations / owner relationships)
• Reuse existing Crossplane patterns:
  • no special-case UX
  • no new presentation logic
• Integrate with existing flows:
  • trace
  • tree composition
  • map / ownership summaries

Explicit Non-Goals

• No cloud-provider API calls
• No speculative inference
• No UX redesign
• No regression to Crossplane behavior

Tests / Proofs of Success

Unit / contract tests

• Fixture set with:
  • kro-managed resource
  • kro root abstraction
• Assert resolver returns:
  • root abstraction
  • partial lineage when metadata is missing

Trace

• cub-scout trace <kro-managed-resource> shows:
  • Managed → kro root
  • (partial lineage) when appropriate

Tree

• cub-scout tree composition groups kro resources under the kro root

Map

• kro-managed resources do not appear as orphans
• Crossplane behavior remains unchanged