[F2-STORY-156] Implement OCI and IBM direct ingest

[duksh]

Execution Metadata

• Issue ID: F2-STORY-156
• Phase: P13
• Type: STORY
• Owner Team: integration-team
• Priority: P1
• Status (initial): Todo
• Depends On: F2-EPIC-155

Acceptance Criteria

OCI and IBM adapters move from placeholder to real ingest

Artifact Paths

• docs/billing-adapter-oci-contract.md
• docs/billing-adapter-ibm-contract.md

Quality Gates

• contract-drift
• security-sbom

Labels (from registry)

oci,ibm

Source Registry

• docs/roadmap/ficecal-v2-task-issue-registry.csv
• docs/roadmap/ficecal-v2-execution-plan-updated.md
• docs/roadmap/ficecal-v2-recovery-index.md