CCIX-213: Expose lifecycle UNKNOWN causes

[yti93]

Why

Lifecycle UNKNOWN findings currently conflate unsupported versions, source failures, malformed data, and inventory gaps, preventing operators from distinguishing healthy unsupported coverage from broken lifecycle inputs.

What

• Add bounded UNKNOWN causes and lifecycle data sources to findings, snapshots, and Prometheus aggregates without engine/version labels
• Preserve endoflife.date response provenance and classify product, cycle, malformed-payload, and source failures
• Add machine-readable local override ownership/review metadata with strict validation and warn-only overdue reviews
• Document the new diagnostics and override operating contract

Risk Assessment

Medium — this changes lifecycle lookup diagnostics and adds metrics/snapshot fields, while preserving existing status counts, Temporal activity contracts, snapshot schema v4, and graceful UNKNOWN behavior.

References

• CCIX-213

Generated with Amp