[maxmad64bis]

⚠️ base-red inherited: #13866

Summary

When a call-log artifact exceeds the size cap, the storage fallback dropped the whole pipeline (including the upstream reply) before omitting the request and response bodies. Bodies are now omitted first, so an artifact that only overflows through its request body keeps the provider response — the part that says why a call failed. Artifacts whose pipeline alone overflows keep the previous behavior.

Related Issues

• Related to fix(backend): call_log_artifact_size_limit_exceeded on stepfun/step-3.7-flash #12420 (artifact rejected instead of truncated on oversize payloads).

Validation

• Change type: other (observability storage fallback)
• Focused tests and category gates from the golden path
• npm run lint — ESLint on the two touched files is clean; the full run is red on the base (🔴 Release branch not green: release/v3.8.51 #13866), unrelated to this diff
• Reconciled with the current active release base; focused checks rerun afterward
• Production-code changes include a new or updated automated test in this PR

Tests Added Or Updated

• tests/unit/call-log-artifact-bodies-first.test.ts (extended, RED-then-GREEN: body-overflow keeps pipeline.provider_response, pipeline-only keeps the previous fallback, double size assertion against the same budget as the code)
• Neighbors re-run green: size-limit-error, pipeline-precedence, file-rotation, log-export-runner (34 pass)

Coverage Notes

• src/lib/usage/callLogArtifacts.ts is covered by the extended test file (7 cases over the reordered fallback).
• No coverage movement beyond the fallback reorder.

Reviewer Notes

• File-size gate: pass; complexity gate: pass (2903 vs baseline 3218, cognitive 1316 vs 1437). typecheck:core is clean and ESLint on touched files is clean.
• No cap raised, truncateArtifactForStorage and the debug-file path untouched; inherited set matches feat(db): add per-proxy egress IP lookup by host and port #14250 (identical comparison with third-party fix(translator): parse DeepSeek Web DSML tool calls #14249, comm empty).
• CI reds are inherited from the red base (🔴 Release branch not green: release/v3.8.51 #13866), not from this diff: the third-party PR fix(sse): treat antigravity empty completions with a normal stop as valid 200s (#14160) #14243 on the same base release/v3.8.51 fails the same 9 jobs (API Route Typecheck, Docs Gates, Fast Quality Gates, Merge integrity, ESLint, Unit fast-path 1-4/4); every file cited by the failing gates is outside this diff. Non-blocking for this PR.