Two corrections, both found by the deep review.
1. The number printed large beside the sale price is NOT the JAN's last three
digits. Checked against the manufacturer, キユーピー ゼロ ノンコレステロール 310g
is JAN 4901577092381 - it ends in 381, not the 357 the tag prints. The number is
the regular (pre-discount) price, and all three tags on the demo shelf confirm it
against their printed discount: (357-269)/357 = 24.6 % -> 2.4割引,
(400-379)/400 = 5.25 % -> 0.5割引, (248-199)/248 = 19.8 % -> 1.9割引. The field
is renamed `regular_price`, the barcode keeps its own name, and the discount is
now a second arithmetic check alongside the tax-included price - so a tag can be
checked against itself twice.
2. A price is only readable when that arithmetic corroborates it. Measured on a live
walk before this: 90 tracks carried a tag marked readable, with prices of 20, 23,
36, 50, 72, 2002 and 4508. The gate has three strengths - an exact tax pair, an
agreeing printed discount, or both plus agreeing digits - and `TagRecord.state`
now consults it, so the wire cannot call an uncorroborated read readable.
Also fixed while measuring: voting picks each field independently, so a record could
publish a price from one frame beside a tax-included price from another (measured:
price 149 with unit 214.92, which never appeared together - 214.92/1.08 = 199). The
arithmetic is now re-run on the values actually being published, stale flags are
dropped, and an implausible regular price (3050 beside 349) is suppressed rather
than published with a discount derived from it.
Measured through the real still path: readable tags 9 -> 5, every published price
now satisfies its own tax-included price, and the live walk publishes none instead
of publishing garbage. 162 tests pass.
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
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