quantmodel — Connect custom Meta payload/export boundary

Objective

Connect custom Meta payload/export boundary.

Notes: Added snapshot-addressed schema-1 custom Meta payload/export with normalized config, encoded URL config, universe digest, catalog revision, coverage boundaries, disclosures, and fail-closed empty-AS validation.

Approach

Reuses existing report research/findings/custom-meta-export-t259.md — tables/metrics preserved verbatim via source_report pointer. Body below summarizes grounded evidence from that report and adjacent artifacts.

Files / code / data changed

No commit SHA confidently associated with t259 in sampled log [reconstructed — uncertain].
Source report: research/findings/custom-meta-export-t259.md
Task-history entry: research/findings/task-history.json#t259

Results

Conclusions and metrics are in research/findings/custom-meta-export-t259.md; see detail page for preserved tables/metrics.

Conclusions

[reconstructed — uncertain] Outcome inferred from status done and task note.

Problems / follow-ups

See source report or PR discussion for follow-ups. No unsupported follow-ups fabricated.