feat(attestation): preserve chainloop.* annotations in NormalizedMaterial

[migmartri]

Summary

• normalizeMaterial() was stripping all chainloop.* prefixed annotations from NormalizedMaterial.Annotations, making internal system annotations (e.g. chainloop.material.size, chainloop.material.cas, chainloop.material.tool.name) unavailable to downstream consumers
• Removed the continue that skipped chainloop.* keys so all annotations flow through to the map
• Added a structValueToString helper to correctly serialize all structpb value types — necessary because some annotations like chainloop.material.cas are stored as BoolValue (for which GetStringValue() returns "")

Closes #2872

[cubic-dev-ai]

1 issue found across 4 files

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="pkg/attestation/renderer/chainloop/v02.go">

<violation number="1" location="pkg/attestation/renderer/chainloop/v02.go:532">
P2: `structValueToString` still drops non-scalar annotation values by converting them to an empty string.</violation>
</file>

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