[bokelley]

This is a follow-up to #8972 (#8968). The training agent doesn't list the experimental media_buy.installment_creative_assignment. #8972 says a seller without the feature MUST reject installment_refs with UNSUPPORTED_FEATURE, and this PR makes the training agent do that.

Change

server/src/training-agent/assignment-operations.ts gets one check, beside the existing trackers and landing_page_url capability checks. It refuses installment_refs on any assignment operation with UNSUPPORTED_FEATURE, and field is assignment_operations[i].installment_refs. Because the request is atomic, nothing is applied.

Until now the training agent ignored the field:

• an assign or replace applied to every installment;
• an unassign carrying the field got past the agent's request handling and removed the creative from every installment, even though the schema rejects installment_refs on unassign.

Test

A new case in server/tests/unit/assignment-operations.test.ts covers assign, replace and unassign with installment_refs. Each must return UNSUPPORTED_FEATURE on that field, the existing assignment must be unchanged afterwards with no installment_refs in readback, and get_adcp_capabilities must not list the feature. The file passes 22/22.

There's no changeset: this is training-agent code, and check-changeset-protocol-scope finds no protocol-scoped changes.

Local hook notes (CI is the gate)

Release Planning approved both skips for this commit.

• Committed with HUSKY=0. Staging server/src runs the full precommit:server-unit suite, which exceeds its 1500s budget at host load ~185. I ran these instead:
  • test:unit: one 10s load timeout in tests/ipr-check-and-record.test.mjs, which passes alone (23/23); its other steps pass, including test:auction-only-compliance (182/182).
  • The test:test-dynamic-imports, test:format-identity-boundaries and test:callapi-state-change guards, and typecheck: all pass.
  • The server unit files nearest the change: assignment-operations (22/22; the only server unit test that touches assignment operations), training-agent-served-release-fields, training-agent-creative33-buyer and tenant-smoke. That's 102/104. The two tenant-smoke cases with a fixed 15s timeout pass once the timeout is raised locally; that edit wasn't committed.
• Pushed with ADCP_SKIP_STORYBOARD_MATRIX=1. The local matrix is advisory, and training-agent-storyboards.yml is the gate.

🤖 Generated with Claude Code

[aao-secretariat]

Ladon verdict: Approve

Approve.

Clean implementation of #8972's UNSUPPORTED_FEATURE refusal for installment_refs. The change adds one unconditional capability check at assignment-operations.ts:102, placed alongside the existing trackers/landing_page refusals and returning before locate() so the atomic request applies nothing — correct behavior with no kind guard since installment_refs can ride assign/replace/unassign. New test covers all three operation kinds plus unchanged-readback and capabilities-absent.

Non-protocol scope (static/schemas/source/** untouched), so no changeset is required — consistent with check-changeset-protocol-scope. No high-risk paths, no gated paths, no author-team gate, no prior decision. No medium-or-worse findings reported.

Decision table: rows 1-8 do not fire (no findings, gated_paths false, high_risk false, no team gate). Falls through to row 9 — approve. Note: review_decision is REVIEW_REQUIRED but gated_paths is false, so row 2 does not apply.