quantmodel — Add meta-strategy result and export contract

Objective

Add meta-strategy result and export contract.

Notes: Added MetaStrategyResult validation plus schema-v1 offline JSON builder/writer with SQLite AS targets, historical/current constituent and asset weights, aligned return/equity charts, tests, and meta-result-export-t185.md.

Approach

Reuses existing report research/findings/meta-result-export-t185.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 t185 in sampled log [reconstructed — uncertain].
Source report: research/findings/meta-result-export-t185.md
Task-history entry: research/findings/task-history.json#t185

Results

Conclusions and metrics are in research/findings/meta-result-export-t185.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.