ai-integrations: implement AIResourceOciProcessor for OCI ingestion

[johnmcollier]

Summary

Implement AIResourceOciProcessor in the ai-integrations workspace for OCI-backed AIResource entities. The processor should validate OCI location format during catalog ingestion, make zero outbound registry or network calls, and be registered in the catalog backend module.

This issue is intentionally scoped to the OCI processor path only and should stay aligned with RHIDP-14556.

Tasks

• Implement AIResourceOciProcessor as a CatalogProcessor for AIResource entities with spec.location.type: oci
• Validate spec.location.target format during processing and reject malformed OCI targets with an actionable error
• Ensure the processor makes zero outbound HTTP or registry network calls
• Register AIResourceOciProcessor in the catalog backend module
• Add focused tests covering valid OCI targets, malformed OCI targets, and zero-network behavior

Acceptance Criteria

• Valid OCI-backed AIResource entities are accepted and ingested successfully
• Malformed OCI targets are rejected during processing with an actionable validation error
• The OCI processor makes zero HTTP or registry network calls
• The processor is registered in the catalog backend module and runs for OCI-backed AIResource entities

Specifications

All paths below are relative to workspaces/ai-integrations/.

• openspec/changes/ai-resource-catalog-entity-kind/design.md
• openspec/changes/ai-resource-catalog-entity-kind/tasks.md (Section 2: Catalog Ingestion - OCI Processor)
• openspec/changes/ai-resource-catalog-entity-kind/specs/ai-resource-catalog-ingestion/spec.md

Out of Scope

• spec.scope schema extension work
• Generalized AIResource validation/error-formatting work outside the OCI processor
• Git-backed ingestion verification beyond ensuring the OCI processor does not interfere with the existing path
• AIResource entity page rendering
• Discovery, filtering, and search support
• Example catalog-info.yaml files and broader documentation follow-up

Context

This issue corresponds to the OCI processor portion of the AIResource catalog work previously tracked in Jira as RHIDP-14556.

Keep the implementation focused on processor behavior and registration. Do not expand this issue into broader schema work or the follow-on validation work tracked separately from RHIDP-14556.