validation-discounts: driving cases → the settled validation-only model (all
money/paper at the booth) → setup UX/storage/RBAC → full as-built record.
DECIDED: merchant stations scan with a USB/HID barcode scanner on the
web/desktop app (hand-keying + Luhn as fallback); POSTPONED with analysis:
web getUserMedia scanning (secure-context TLS prerequisite on the LAN +
Code128-via-camera weakness → QR-on-ticket first) and a Tauri v2 Android
merchant app (native ML Kit scanning; Android build/sideload overhead +
configurable-server-URL prerequisite). Also: wsl-dev-networking gains the
mirrored-mode gotcha where a Windows-side listener makes a port EADDRINUSE
inside WSL while invisible to ss — Vite auto-increments and tauri dev's fixed
devUrl waits on the wrong port.
Claude-Session: https://claude.ai/code/session_01YYkpEsLmoQPaize5ec3oUm
Ingest the predecessor SQL Server schema (raw + source summary) and file design
pages for time-of-day/seasonal tariff tiers and merchant validation/postpaid
sponsorship. Cross-link tariff.md and validation-discounts.md. No code.