feat: add Shift Planning module with full CRUD, attendance, and reporting

- Add shifts, shift_staff, and shift_attendance migrations
- Add Shift, ShiftStaff, ShiftAttendance Eloquent models with auditing
- Add ShiftService with business logic (create, start, complete, assign staff, mark attendance, reports, timesheets)
- Add ShiftResource with list, create, edit, and attendance management pages
- Add staff and attendance relation managers
- Add standalone pages: ActiveShifts, StaffManagement, ShiftReports, Timesheets
- Add dashboard widgets: ShiftOverview stats, TodaysShifts table
- Add ShiftPolicy for role-based authorization
- Add 10 shift permissions and manager role to RolePermissionSeeder
- Update User model with shift relationships
- Fix audits table migration with required columns for owen-it/laravel-auditing
- Update DatabaseSeeder to create admin user and call RolePermissionSeeder
- Switch docker-compose to MariaDB 10.11 for Docker Desktop compatibility

src/app/Models/User.php

@@ -4,6 +4,8 @@
 
 // use Illuminate\Contracts\Auth\MustVerifyEmail;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Foundation\Auth\User as Authenticatable;
 use Illuminate\Notifications\Notifiable;
 use Laravel\Sanctum\HasApiTokens;
@@ -47,4 +49,23 @@ protected function casts(): array
             'password' => 'hashed',
         ];
     }
+
+    // --- Shift Relationships ---
+
+    public function shifts(): BelongsToMany
+    {
+        return $this->belongsToMany(Shift::class, 'shift_staff')
+            ->withPivot('assigned_by')
+            ->withTimestamps();
+    }
+
+    public function shiftAttendances(): HasMany
+    {
+        return $this->hasMany(ShiftAttendance::class);
+    }
+
+    public function createdShifts(): HasMany
+    {
+        return $this->hasMany(Shift::class, 'created_by');
+    }
 }