Sequel to the 2026-05-22 tablet redesign (Phases 1-5). Adds a tile-grid
lock screen + 4-digit PIN per tech + 5-min auto-lock + audit propagation
so multiple techs sharing one tablet get correctly-attributed actions.
Key design choices:
- 4-digit PIN (industry norm), PBKDF2-SHA256 with 200k iterations
- Per-user lockout after 5 failures (not per-tablet)
- Single Odoo session + tablet_tech_id kwarg for audit (no JS reload on
every tech switch)
- Manager-side reset only (no SMS/email infra)
- Server-side step timer keeps running on lock (auto-pause cron is
the upper-bound safety net)
Three sub-phases (6.1 backend / 6.2 frontend lock / 6.3 audit kwarg
propagation), each independently deployable.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
233e5e6e72