quantmodel — Fix Custom Meta report versioned-input loading error

Objective

Fix Custom Meta report versioned-input loading error.

Notes: Fixed hosted/static versioned-input lookup by routing both immutable input and worker URLs through shared site-root resolution; preserved fail-closed errors and added real Chromium base-prefix regression plus durable feature-completion evidence.

Approach

Reuses existing report research/findings/custom-meta-versioned-input-t353.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 t353 in sampled log [reconstructed — uncertain].
Source report: research/findings/custom-meta-versioned-input-t353.md
Task-history entry: research/findings/task-history.json#t353

Results

Conclusions and metrics are in research/findings/custom-meta-versioned-input-t353.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.