feat : Track ResourceGraphDefinition changes and require opt-in for instance updates

[shivansh-source]

This PR addresses issue #188 by making instance updates from a
ResourceGraphDefinition (RGD) explicit, traceable, and safe by default.

This PR introduces:

RGD change tracking on instances
Adds two status fields:
resourceRevision: a stable sha256 hash of the compiled graph.Graph
resourceGroupGeneration: a monotonic counter derived from revision changes
These track effective RGD changes without requiring access to Kubernetes metadata.generation
Opt-in update mechanism
Instances only receive RGD updates when annotated with:

kro.run/allow-updates: "true"

By default, updates are blocked and surfaced via conditions
Safe reconciliation behavior
First-time and legacy instances are initialized automatically
Non–opted-in instances are not mutated when the RGD changes
Opted-in instances update normally and refresh their tracked revision/generation.

Testing

Unit tests pass locally

Integration tests require envtest binaries (etcd, kube-apiserver) and were not run locally; CI should execute them

Fixes #188.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: shivansh-source / name: shivansh-source (d3092fe)

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[shivansh-source]

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