PBKDF2-SHA256 + 16-byte salt + 200k iterations on res.users. Format
of the stored hash string is <salt_hex>$<digest_hex>. Field is
manager-readable only (groups=group_fusion_plating_manager); helpers
that need to read or write it use .sudo() internally so operator-level
callers can still set/verify their own PIN.
Adds set_tablet_pin / verify_tablet_pin / clear_tablet_pin model
methods + action_open_tablet_pin_setup that triggers the OWL setup
modal (Phase 6.2). Tests cover hash uniqueness, verify, clear with
chatter post, and the 4-digit format guard.
Tests verified on entech: -u fusion_plating_shopfloor --test-tags fp_tablet_pin
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
395bd4949e