feat(fusion_plating_shopfloor): /fp/tablet/unlock with per-user lockout (P6.1.3)

Verifies PIN, resets failure counter on success, increments + locks out
on 5 consecutive failures (configurable via ir.config_parameter
fp.shopfloor.tablet_pin_fail_threshold + tablet_pin_fail_lockout_minutes,
both defaulting to 5).

Returns informative payloads:
  ok=true            current_tech_id, current_tech_name
  needs_setup=true   user has no PIN yet
  locked_until       lockout in effect (rejects even correct PIN)
  attempts_remaining failed but not yet locked

Logs INFO on success, WARNING on failure (with running counter +
locked flag).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

fusion_plating/fusion_plating_shopfloor/tests/test_tablet_pin.py

@@ -124,3 +124,60 @@ class TestTabletResetPinFor(HttpCase):
         self.assertTrue(res['ok'])
         self.target.invalidate_recordset(['x_fc_tablet_pin_hash'])
         self.assertFalse(self.target.sudo().x_fc_tablet_pin_hash)
+
+
+@tagged('-at_install', 'post_install', 'fp_shopfloor', 'fp_tablet_pin')
+class TestTabletUnlock(HttpCase):
+    """P6.1.3 — /fp/tablet/unlock endpoint + lockout."""
+
+    def setUp(self):
+        super().setUp()
+        self.authenticate("admin", "admin")
+        self.target = self.env['res.users'].create({
+            'name': 'Unlock Target', 'login': 'unlock@example.com',
+        })
+        self.target.sudo().set_tablet_pin('1234')
+
+    def _unlock(self, pin):
+        return _rpc(self, '/fp/tablet/unlock',
+                    user_id=self.target.id, pin=pin)
+
+    def test_unlock_correct_pin(self):
+        res = self._unlock('1234')
+        self.assertTrue(res['ok'])
+        self.assertEqual(res['current_tech_id'], self.target.id)
+        self.assertEqual(res['current_tech_name'], 'Unlock Target')
+
+    def test_unlock_correct_pin_resets_fail_counter(self):
+        self._unlock('0000')  # fail once
+        self._unlock('1234')  # succeed
+        self.target.invalidate_recordset(['x_fc_tablet_pin_failed_count'])
+        self.assertEqual(self.target.sudo().x_fc_tablet_pin_failed_count, 0)
+
+    def test_unlock_wrong_pin_increments_counter(self):
+        self._unlock('0000')
+        self.target.invalidate_recordset(['x_fc_tablet_pin_failed_count'])
+        self.assertEqual(self.target.sudo().x_fc_tablet_pin_failed_count, 1)
+
+    def test_lockout_after_5_fails(self):
+        for _ in range(5):
+            self._unlock('0000')
+        res = self._unlock('0000')  # 6th
+        self.assertFalse(res['ok'])
+        self.assertIn('locked', res['error'].lower())
+        self.target.invalidate_recordset(['x_fc_tablet_locked_until'])
+        self.assertTrue(self.target.sudo().x_fc_tablet_locked_until)
+
+    def test_lockout_blocks_even_correct_pin(self):
+        for _ in range(5):
+            self._unlock('0000')
+        # Even the correct PIN now rejected
+        res = self._unlock('1234')
+        self.assertFalse(res['ok'])
+        self.assertIn('locked', res['error'].lower())
+
+    def test_unlock_no_pin_set(self):
+        self.target.clear_tablet_pin()
+        res = self._unlock('1234')
+        self.assertFalse(res['ok'])
+        self.assertTrue(res.get('needs_setup'))