security: round 1 — quick wins (rate limiting, headers, mass assignment, logging)

- Add throttle middleware to login (5/min), portal/token-auth (10/min),
  volunteer-register (5/min), and invitation routes (10/min)
- Set Sanctum token expiration to 7 days
- Remove billing_status from UpdateOrganisationRequest (super_admin only)
- Revoke all Sanctum tokens on password reset
- Strengthen password rules: min 8 chars, mixed case, numbers
- Create SecurityHeaders middleware (X-Content-Type-Options, X-Frame-Options,
  HSTS, Referrer-Policy, Permissions-Policy)
- Fix open redirect on all 3 login pages (validate ?to= starts with /)
- Set APP_DEBUG=false in .env.example
- Log failed login attempts with email, IP, user-agent
- Log authorization failures (403) with user, IP, path, method
- Harden mass assignment: remove user_id from Person, audit fields from
  ShiftAssignment, system fields from UserInvitation $fillable
- Replace real DB records with factory make() in mail preview routes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/database/factories/ShiftAssignmentFactory.php

@@ -22,25 +22,34 @@ final class ShiftAssignmentFactory extends Factory
             'person_id' => Person::factory(),
             'time_slot_id' => TimeSlot::factory(),
             'status' => ShiftAssignmentStatus::PENDING_APPROVAL,
-            'auto_approved' => false,
-            'assigned_at' => now(),
         ];
     }
 
+    public function configure(): static
+    {
+        return $this->afterCreating(function (ShiftAssignment $assignment): void {
+            $assignment->auto_approved = false;
+            $assignment->assigned_at = now();
+            $assignment->save();
+        });
+    }
+
     public function approved(): static
     {
-        return $this->state(fn () => [
-            'status' => ShiftAssignmentStatus::APPROVED,
-            'approved_at' => now(),
-        ]);
+        return $this->afterCreating(function (ShiftAssignment $assignment): void {
+            $assignment->status = ShiftAssignmentStatus::APPROVED;
+            $assignment->approved_at = now();
+            $assignment->save();
+        });
     }
 
     public function autoApproved(): static
     {
-        return $this->state(fn () => [
-            'status' => ShiftAssignmentStatus::APPROVED,
-            'auto_approved' => true,
-            'approved_at' => now(),
-        ]);
+        return $this->afterCreating(function (ShiftAssignment $assignment): void {
+            $assignment->status = ShiftAssignmentStatus::APPROVED;
+            $assignment->auto_approved = true;
+            $assignment->approved_at = now();
+            $assignment->save();
+        });
     }
 }