feat(security): argon2id password hashing and AES for SignRSA secrets

- Hash driver read from HASH_DRIVER (argon2id in production); bcrypt
  hashes still verify and are rehashed on successful admin/client login
  since the JWT guard and guard->validate() never rehash on their own.
- Client registration uses Hash::make instead of bcrypt(), which always
  forced bcrypt regardless of the configured driver.
- SignRSA now encrypts with Crypt (AES-256-CBC + HMAC, APP_KEY) instead
  of 3DES in ECB mode without IV. Legacy 3DES values are still readable
  via RSA_KEY/RSA_PUBLIC until `secrets:reencrypt` migrates them;
  RSA_PRIVATE is no longer used.
- LegacyPortalImporter stored module_vmware.password in plaintext; it is
  now encrypted, and a migration encrypts existing plaintext rows.

Deploy: php artisan migrate, then secrets:reencrypt --dry-run and
secrets:reencrypt; remove RSA_* from env once it exits 0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/Http/Controllers/Api/Admin/Auth/AuthController.php

@@ -55,6 +55,7 @@ class AuthController extends Controller
         RateLimiter::clear($throttleKey);
 
         $user = Auth::guard('admin')->user();
+        Auth::guard('admin')->getProvider()->rehashPasswordIfRequired($user, $request->only('password'));
 
         $this->activityLogger->logAuth('login', 'admin', $user->id, $user->username ?? $user->email);