compliance: add vendor_metric optimization-goal storyboard coverage

[bokelley]

Problem

3.1 adds optimization_goals[].kind: "vendor_metric" plus product-level vendor_metric_optimization.supported_metrics[]. Existing vendor-metric storyboard coverage (media_buy_seller/vendor_metric_accountability) covers declaration → filter → delivery emission, but not optimization-goal acceptance/rejection.

A seller can currently pass the vendor-metric reporting storyboard without proving it enforces the 3.1 vendor-metric optimization contract.

Scope

Add a media-buy storyboard that exercises the full vendor-metric optimization path:

1. Product discovery returns vendor_metric_optimization.supported_metrics[] for a (vendor, metric_id) pair and target kind.
2. Create media buy accepts an optimization_goals[] entry with kind: "vendor_metric" when all preconditions are met.
3. Seller rejects a vendor-metric goal when the product lacks matching vendor_metric_optimization capability.
4. Seller rejects a vendor-metric goal when the package lacks matching vendor-scope committed_metrics[].
5. When possible, seller rejects or advisories a goal whose metric_id is not discoverable in the vendor metric catalog, matching the 3.1 SHOULD / next-minor MUST cadence.

Acceptance

• New storyboard or scenario under static/compliance/source/protocols/media-buy/scenarios/ covers positive and negative paths.
• Training-agent fixtures include a product with vendor_metric_optimization.supported_metrics[].
• Negative paths assert TERMS_REJECTED or the canonical error specified by the task reference.
• The existing vendor-metric declaration/filter/emission storyboard remains intact.
• npm run test:storyboards stays green.

References

• Closed issue for reporting-only fixture: Storyboard fixture for vendor-metric extensions (declaration → filter → emission) #3501
• Meta capability-claim tracker: Meta: capability-claim contract scenarios — close the gap between what agents declare and what they do #4637
• Release notes: Optimization goals — kind: "vendor_metric"
• Existing storyboard: static/compliance/source/protocols/media-buy/scenarios/vendor_metric_accountability.yaml

[bokelley]

Triage

Classification: Feature request / compliance gap
Bucket(s): compliance-suite, media-buy
Status: drafting-pr
Milestone: 3.1.0

What the experts said:

• ad-tech-protocol-expert: paths 1–4 are fully normatively grounded; INVALID_REQUEST (not TERMS_REJECTED) is correct for both negative paths; no requires_capability gate needed since vendor_metric_optimization is product-level only; path 5 (SHOULD cadence) is correctly handled as advisory-only
• code-reviewer: single-file approach is correct; single product fixture with both reporting_capabilities.vendor_metrics and vendor_metric_optimization.supported_metrics[]; training-agent additions go in TypeScript (publishers.ts + product-factory.ts), not the storyboard fixtures: block

My take: Non-breaking, clear spec backing in 3.1 schemas, well-specified acceptance criteria. Drafting PR with positive path + two negative paths (capability mismatch, reporting-coherence mismatch). Path 5 (vendor catalog SHOULD) documented in narrative only — tightens to MUST at next minor.

Drafting PR: #4939 — new storyboard vendor_metric_optimization_flow.yaml + training-agent fixture additions.

One unexercised MUST-level path noted by review (target.kind not in supported_targets) — scope for a follow-up issue.

---

Triaged by Claude Code. Session: https://claude.ai/code/session_01VtKu8sAUEWAHRPMiZJBgHw

---

Generated by Claude Code