fix(ai): treat unchanged AI settings as successful save

update_option returns false when values are identical, which made
POST /ai/settings respond 400 with "保存失败" on no-op saves and
masked-key re-saves. Normalize config, accept no-op as success, and
only send a new API key from the admin form when entered.

assets/admin/src/pages/extensions/ExtensionAI.vue

@@ -216,9 +216,17 @@ export default {
     async function saveSettings() {
       saving.value = true;
       try {
-        const payload = { ...form };
+        const payload = {
-        if (!payload.api_key && status.value.configured) {
+          enabled: form.enabled,
-          payload.api_key = '***';
+          provider: form.provider,
+          api_base: form.api_base,
+          model: form.model,
+          max_tokens: form.max_tokens,
+          rate_limit: form.rate_limit,
+        };
+        // Only send api_key when the user entered a new one.
+        if (form.api_key && form.api_key !== '***') {
+          payload.api_key = form.api_key;
         }
         const json = await api.updateAiSettings(payload);
         alert(json.message || '设置已保存');

inc/classes/admin/class-aksrt-admin-ai-controller.php

@@ -130,7 +130,10 @@ class AKSRT_Admin_AI_Controller extends AKSRT_Admin_Controller_Base {
 
         $success = AKSRT_AI::get_instance()->update_config($config);
         if ($success) {
-            return $this->success(['message' => __('AI 设置已保存', 'aksrt')]);
+            return $this->success([
+                'message' => __('AI 设置已保存', 'aksrt'),
+                'data'    => AKSRT_AI::get_instance()->get_status(),
+            ]);
         }
         return $this->error(__('保存失败', 'aksrt'));
     }

inc/classes/class-aksrt-ai.php

@@ -54,11 +54,60 @@ class AKSRT_AI {
         $current = $this->get_config();
         $merged  = array_merge($current, $config);
 
+        // Preserve existing key when client sends the masked placeholder.
         if (isset($config['api_key']) && $config['api_key'] === '***') {
             $merged['api_key'] = $current['api_key'];
         }
 
-        return update_option('aksrt_ai_settings', $merged);
+        $merged['enabled']    = !empty($merged['enabled']);
+        $merged['provider']   = sanitize_key((string) ($merged['provider'] ?? self::PROVIDER_NONE));
+        $merged['api_key']    = (string) ($merged['api_key'] ?? '');
+        $merged['api_base']   = esc_url_raw((string) ($merged['api_base'] ?? 'https://api.openai.com/v1'));
+        $merged['model']      = sanitize_text_field((string) ($merged['model'] ?? 'gpt-3.5-turbo'));
+        $merged['max_tokens'] = max(100, min(4000, (int) ($merged['max_tokens'] ?? 1000)));
+        $merged['rate_limit'] = max(1, min(100, (int) ($merged['rate_limit'] ?? 10)));
+
+        // Persist only the known keys so shape stays stable.
+        $to_store = [
+            'enabled'    => $merged['enabled'],
+            'provider'   => $merged['provider'],
+            'api_key'    => $merged['api_key'],
+            'api_base'   => $merged['api_base'],
+            'model'      => $merged['model'],
+            'max_tokens' => $merged['max_tokens'],
+            'rate_limit' => $merged['rate_limit'],
+        ];
+
+        $before  = get_option('aksrt_ai_settings', []);
+        $updated = update_option('aksrt_ai_settings', $to_store);
+        if ($updated) {
+            return true;
+        }
+
+        // update_option returns false when the value is unchanged — treat as success.
+        if (is_array($before)) {
+            $before_normalized = array_merge([
+                'enabled'    => false,
+                'provider'   => self::PROVIDER_NONE,
+                'api_key'    => '',
+                'api_base'   => 'https://api.openai.com/v1',
+                'model'      => 'gpt-3.5-turbo',
+                'max_tokens' => 1000,
+                'rate_limit' => 10,
+            ], $before);
+            $before_normalized['enabled']    = !empty($before_normalized['enabled']);
+            $before_normalized['provider']   = sanitize_key((string) ($before_normalized['provider'] ?? self::PROVIDER_NONE));
+            $before_normalized['api_key']    = (string) ($before_normalized['api_key'] ?? '');
+            $before_normalized['api_base']   = esc_url_raw((string) ($before_normalized['api_base'] ?? 'https://api.openai.com/v1'));
+            $before_normalized['model']      = sanitize_text_field((string) ($before_normalized['model'] ?? 'gpt-3.5-turbo'));
+            $before_normalized['max_tokens'] = max(100, min(4000, (int) ($before_normalized['max_tokens'] ?? 1000)));
+            $before_normalized['rate_limit'] = max(1, min(100, (int) ($before_normalized['rate_limit'] ?? 10)));
+
+            return maybe_serialize($before_normalized) === maybe_serialize($to_store)
+                || $before_normalized == $to_store;
+        }
+
+        return maybe_serialize($before) === maybe_serialize($to_store);
     }
 
     /**