Implement repaired AAII workbook ingestion

Objective

Implement repaired AAII workbook ingestion.

Notes: Added checksum/provenance-aware public asset.xls downloader and parser; repairs only the 22 documented 2006/07 date cells, retains original dates/source rows, rejects all other discontinuities, maps unrounded stock-fund plus individual-stock totals into validated point-in-time observations, and does not persist raw history. Live checksum 3a32... produced 240 monthly rows (2006-07 through 2026-06), 22 repairs, and June 2026 total stocks 71.0292%.

Approach

[reconstructed — uncertain] No dedicated findings Markdown located for t347. Summary reconstructed from research/findings/task-history.json entry and git history. Uncertain fields: detailed approach, exact file list, and metrics beyond the task note.

Files / code / data changed

• No commit SHA confidently associated with t347 in sampled log [reconstructed — uncertain].
• Task-history entry: research/findings/task-history.json#t347

Results

Task note: Added checksum/provenance-aware public asset.xls downloader and parser; repairs only the 22 documented 2006/07 date cells, retains original dates/source rows, rejects all other discontinuities, maps unrounded stock-fund plus individual-stock totals into validated point-in-time observations, and does not persist raw history. Live checksum 3a32... produced 240 monthly rows (2006-07 through 2026-06), 22 repairs, and June 2026 total stocks 71.0292%. [reconstructed — uncertain] No quantitative tables recovered for this entry; see git diff and task-history for grounds.

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.

Links

• Task-history: research/findings/task-history.json id t347