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/PersonFactory.php

@@ -29,6 +29,29 @@ final class PersonFactory extends Factory
         ];
     }
 
+    /**
+     * Override create to handle user_id which is not mass-assignable.
+     *
+     * @param  array<string, mixed>  $attributes
+     */
+    public function create($attributes = [], ?\Illuminate\Database\Eloquent\Model $parent = null): Person|\Illuminate\Database\Eloquent\Collection
+    {
+        $userId = $attributes['user_id'] ?? null;
+        unset($attributes['user_id']);
+
+        $result = parent::create($attributes, $parent);
+
+        if ($userId !== null) {
+            $models = $result instanceof Person ? collect([$result]) : $result;
+            $models->each(function (Person $person) use ($userId): void {
+                $person->user_id = $userId;
+                $person->save();
+            });
+        }
+
+        return $result;
+    }
+
     public function approved(): static
     {
         return $this->state(fn () => ['status' => 'approved']);