feat(decisioning): dev-mode warn on multi-id truncation in getMediaBuyDelivery / getMediaBuys

[bokelley]

Refs #1399

Adds a dev-mode logger.warn in the dispatch path of getMediaBuyDelivery and getMediaBuys when the platform returns fewer rows than the buyer's media_buy_ids[] requested. This catches the "truncate-to-media_buy_ids[0]" footgun at adapter-development time — the class of bug documented in #1342.

What changed

src/lib/server/decisioning/runtime/from-platform.ts

• New private helper warnMultiIdTruncation — fires logger.warn when requestedIds.length > returnedRows.length and NODE_ENV is test or development.
• getMediaBuyDelivery dispatch: expanded from a one-liner to an async body so the result can be inspected before returning.
• getMediaBuys dispatch: call added after the existing autoStoreResources call.
• Follows the exact isDevOrTest guard pattern from lines 756 and 773, and the ADCP_DECISIONING_ALLOW_* env-var suppression pattern from lines 757 and 774.

test/server-decisioning-multi-id-truncation-warn.test.js (new file)
11 tests across both tools covering: warn fires on truncation; no warn on exact-count match; no warn when media_buy_ids omitted (paginated-list contract); suppressed by ADCP_DECISIONING_ALLOW_MULTI_ID_TRUNCATION=1; silent in NODE_ENV=production; silent when NODE_ENV unset.

Test plan

• All 11 new tests pass
• 121 tests in server-decisioning-from-platform.test.js + related suites pass (0 failures)
• npm run format:check clean
• npm run build:lib (pre-push hook: typecheck + format) clean
• Changeset included (patch — additive dev-mode diagnostic only)

Pre-PR review

• code-reviewer: approved — logic correct, projectSync error path handled (warn only fires on successful responses), === '1' guard matches file convention, 9 acceptance-criteria tests validated. Issues (fix or explain): issue link points to design: media_buy_ids[] fan-out semantics on getMediaBuyDelivery — framework aggregates vs. platform's job #1342 (root footgun, deliberate — more stable than the triage PR URL), missing getMediaBuys paginated-list + production tests added in fixup commit.
• dx-expert: approved with one blocker fixed — warning message now includes Set ADCP_DECISIONING_ALLOW_MULTI_ID_TRUNCATION=1 to silence. matching the established pattern at lines 784 and 965.

Nits surfaced (not fixed — out of PR scope)

• opts.mediaBuy legacy merge-seam path silently bypasses the warning (existing migration path, documented comment at line 3178).
• No over-delivery test (responseRows.length > requestedIds.length path — the >= guard handles it correctly but is untested).

Triage-managed PR. This bot does not currently iterate on
review comments or PR conversation threads (only on the source
issue). To unblock:

• Push fixup commits directly: gh pr checkout <num> →
  fix → push.
• Or re-trigger: comment /triage execute on the source
  issue.

See adcp#3121
for context.

Session: https://claude.ai/code/session_01QQQayoudDsHqFnpREANjJ2

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[bokelley]

Closing as superseded — multi-id-truncation-warn shipped via #1408 (commit on main now). Same dev-mode logger.warn on the dispatch path of getMediaBuyDelivery / getMediaBuys when handler returns fewer rows than the buyer's media_buy_ids[] requested. Covered in the migration doc as a paired callout under recipe #14 / 'What else changed'.

[bokelley]

Acknowledged — superseded by #1408, which shipped the same logger.warn on multi-id truncation in getMediaBuyDelivery / getMediaBuys. No further action needed on this draft.

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Generated by Claude Code