feat(fusion_plating_shopfloor): res.users tablet PIN fields + hash helpers (P6.1.1)

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>

fusion_plating/fusion_plating_shopfloor/tests/__init__.py

@@ -1,3 +1,4 @@
 # -*- coding: utf-8 -*-
 from . import test_workspace_controller
 from . import test_landing_kanban
+from . import test_tablet_pin

fusion_plating/fusion_plating_shopfloor/tests/test_tablet_pin.py

@@ -0,0 +1,54 @@
+# -*- coding: utf-8 -*-
+# Copyright 2026 Nexa Systems Inc. — License OPL-1
+"""Phase 6 — Tablet PIN gate tests."""
+import json
+
+from odoo.tests.common import HttpCase, TransactionCase, tagged
+
+
+@tagged('-at_install', 'post_install', 'fp_shopfloor', 'fp_tablet_pin')
+class TestTabletPinHash(TransactionCase):
+    """P6.1.1 — model fields + hash helpers + set/verify/clear methods."""
+
+    def setUp(self):
+        super().setUp()
+        self.user = self.env['res.users'].create({
+            'name': 'Pin Test',
+            'login': 'pintest@example.com',
+        })
+
+    def test_set_pin_stores_salted_hash(self):
+        self.user.sudo().set_tablet_pin('1234')
+        stored = self.user.sudo().x_fc_tablet_pin_hash
+        self.assertTrue(stored)
+        self.assertIn('$', stored, 'hash must include salt separator')
+        # Hash is non-deterministic — setting same PIN twice gives different stored values
+        self.user.sudo().set_tablet_pin('1234')
+        self.assertNotEqual(stored, self.user.sudo().x_fc_tablet_pin_hash)
+
+    def test_verify_correct_pin(self):
+        self.user.sudo().set_tablet_pin('1234')
+        self.assertTrue(self.user.sudo().verify_tablet_pin('1234'))
+
+    def test_verify_wrong_pin(self):
+        self.user.sudo().set_tablet_pin('1234')
+        self.assertFalse(self.user.sudo().verify_tablet_pin('0000'))
+
+    def test_verify_pin_no_hash_set(self):
+        self.assertFalse(self.user.sudo().verify_tablet_pin('1234'))
+
+    def test_set_pin_rejects_invalid_format(self):
+        from odoo.exceptions import UserError
+        for bad in ('123', '12345', 'abcd', '', None):
+            with self.assertRaises(UserError):
+                self.user.sudo().set_tablet_pin(bad)
+
+    def test_clear_pin_wipes_hash_and_posts_chatter(self):
+        self.user.sudo().set_tablet_pin('1234')
+        self.user.clear_tablet_pin()
+        self.user.invalidate_recordset(['x_fc_tablet_pin_hash'])
+        self.assertFalse(self.user.sudo().x_fc_tablet_pin_hash)
+        self.assertFalse(self.user.sudo().x_fc_tablet_pin_set_date)
+        # Check chatter
+        last_msg = self.user.message_ids[:1]
+        self.assertIn('reset by', (last_msg.body or '').lower())