TariffWatch v1.2.0: BIS-14 dual-exposure bug fix, E2E harness, and portfolio-wide hardening

A dual-exposure rate calculation bug in the BIS-14 exposure checker was found and fixed, alongside five more sample comment letters and a load-test script for the scan endpoint. A Playwright E2E harness shipped this day too, giving TariffWatch's highest-stakes flow (a legally-consequential comment letter) real regression coverage for the first time.

Ten more fixes closed out account-delete and submit-letter page titles, legal footers, dynamic og:image and twitter:card tags, checker warning copy, retry-after handling, PDF downloads, accessibility labels, the methodology page, and an HTS autocomplete datalist on the Exposure Checker, plus the same portfolio-wide security and observability hardening that shipped across all three picks this day.

The dual-exposure rate bug was the kind of defect that looks correct at a glance and is wrong in a way that specifically matters here: TariffWatch's whole value proposition is telling an importer an accurate exposure number, so a calculation bug in that number is closer to a product-integrity issue than a cosmetic one. The Playwright E2E harness that shipped the same day exists to catch exactly this class of bug before it reaches a real importer relying on the number to decide whether to file a comment.