feat(fusion_clock): native recurring shifts engine [A4-A5]

fusion.clock.schedule.recurrence (repeat every N day/week/month/year;
forever/until/N-times) re-fit from planning.recurrency onto per-day rows;
daily generation cron; _fclk_on_leave skip; planner Repeat…/Stop-repeat
UI + endpoints; recurrence + role indicators on cells.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

fusion_clock/models/hr_employee.py

@@ -173,6 +173,19 @@ class HrEmployee(models.Model):
             ('schedule_date', '=', date_obj),
         ], limit=1)
 
+    def _fclk_on_leave(self, date):
+        """True if an approved leave request covers ``date`` for this employee.
+        Used by the recurrence engine to skip generating shifts on days off."""
+        self.ensure_one()
+        date_obj = fields.Date.to_date(date)
+        if not date_obj:
+            return False
+        return bool(self.env['fusion.clock.leave.request'].sudo().search_count([
+            ('employee_id', '=', self.id),
+            ('leave_date', '<=', date_obj),
+            ('date_to', '>=', date_obj),
+        ]))
+
     def _get_fclk_day_plan(self, date):
         """Return the effective plan for a local date, with an explicit
         ``scheduled`` flag that ALL attendance automation keys off.