feat(admin): manage captcha configuration centrally

- add a dedicated Filament settings tab for captcha drivers
- persist selections into config-compatible schema and migrate legacy keys
- extend captcha manager to consume database overrides transparently

Signed-off-by: Qi HU <github@spcsky.com>

app/Services/Captcha/CaptchaManager.php

@@ -3,6 +3,7 @@
 namespace App\Services\Captcha;
 
 use App\Services\Captcha\Exceptions\CaptchaValidationException;
+use App\Models\Setting;
 use Illuminate\Support\Arr;
 
 class CaptchaManager
@@ -113,6 +114,15 @@ class CaptchaManager
             }
 
             $this->config = is_array($config) ? $config : [];
+
+            try {
+                $settings = Setting::get('captcha', []);
+                if (is_array($settings) && !empty($settings)) {
+                    $this->config = array_replace_recursive($this->config, $settings);
+                }
+            } catch (\Throwable $exception) {
+                // ignore database errors at bootstrap phase
+            }
         }
 
         return Arr::get($this->config, $key, $default);