feat(admin): show common placeholders group in email template editor

Companion to the bot-side change: the variables hint now renders two
groups — type-specific vars and common ones ({service_name},
{cabinet_url}, {support_username}, {username}, {email}, {date}) that
work in every template. The block is visible even for types with no
vars of their own (previously it was hidden entirely, looking like
placeholders didn't exist). Common chips insert at cursor the same way.

src/api/adminEmailTemplates.ts

@@ -15,6 +15,8 @@ export interface EmailTemplateType {
 export interface EmailTemplateListResponse {
   items: EmailTemplateType[];
   available_languages: string[];
+  /** Placeholders available in every template regardless of type */
+  common_context_vars: string[];
 }
 
 export interface EmailTemplateLanguageData {
@@ -30,6 +32,8 @@ export interface EmailTemplateDetail {
   label: Record<string, string>;
   description: Record<string, string>;
   context_vars: string[];
+  /** Placeholders available in every template regardless of type */
+  common_context_vars?: string[];
   languages: Record<string, EmailTemplateLanguageData>;
 }
 

src/locales/en.json

@@ -1547,7 +1547,8 @@
       "insertDefault": "Insert default template",
       "insertDefaultConfirm": "Replace the current content with the default template?",
       "testRecipientPlaceholder": "Recipient email (defaults to yours)",
-      "testHint": "Sends the current editor content with sample values in place of variables."
+      "testHint": "Sends the current editor content with sample values in place of variables.",
+      "variablesCommon": "Common variables (work in all templates)"
     },
     "payments": {
       "title": "Payments",

src/locales/fa.json

@@ -1420,7 +1420,8 @@
       "insertDefault": "درج قالب پیش‌فرض",
       "insertDefaultConfirm": "محتوای فعلی با قالب پیش‌فرض جایگزین شود؟",
       "testRecipientPlaceholder": "ایمیل گیرنده (پیش‌فرض: ایمیل شما)",
-      "testHint": "محتوای فعلی ویرایشگر با مقادیر نمونه به جای متغیرها ارسال می‌شود."
+      "testHint": "محتوای فعلی ویرایشگر با مقادیر نمونه به جای متغیرها ارسال می‌شود.",
+      "variablesCommon": "متغیرهای عمومی (در همه قالب‌ها کار می‌کنند)"
     },
     "wheel": {
       "title": "تنظیمات چرخ شانس",

src/locales/ru.json

@@ -1569,7 +1569,8 @@
       "insertDefault": "Вставить шаблон по умолчанию",
       "insertDefaultConfirm": "Заменить текущее содержимое шаблоном по умолчанию?",
       "testRecipientPlaceholder": "Email получателя (по умолчанию — ваш)",
-      "testHint": "Отправит текущее содержимое редактора с примерами значений вместо переменных."
+      "testHint": "Отправит текущее содержимое редактора с примерами значений вместо переменных.",
+      "variablesCommon": "Общие переменные (работают во всех шаблонах)"
     },
     "payments": {
       "title": "Платежи",

src/locales/zh.json

@@ -1461,7 +1461,8 @@
       "insertDefault": "插入默认模板",
       "insertDefaultConfirm": "用默认模板替换当前内容？",
       "testRecipientPlaceholder": "收件人邮箱（默认为您的邮箱）",
-      "testHint": "发送当前编辑器内容，变量将替换为示例值。"
+      "testHint": "发送当前编辑器内容，变量将替换为示例值。",
+      "variablesCommon": "通用变量（适用于所有模板）"
     },
     "payments": {
       "title": "支付",

src/pages/AdminEmailTemplates.tsx

@@ -362,9 +362,11 @@ function TemplateEditor({
             />
           </div>
 
-          {/* Context variables hint */}
+          {/* Context variables hint: type-specific + common (available in all templates) */}
+          {(detail.context_vars.length > 0 || (detail.common_context_vars?.length ?? 0) > 0) && (
+            <div className="space-y-2.5 rounded-lg border border-dark-700 bg-dark-900/60 p-2.5 sm:p-3">
               {detail.context_vars.length > 0 && (
-            <div className="rounded-lg border border-dark-700 bg-dark-900/60 p-2.5 sm:p-3">
+                <div>
                   <p className="mb-1.5 text-xs font-medium text-dark-300">
                     {t('admin.emailTemplates.variables')}
                   </p>
@@ -382,6 +384,27 @@ function TemplateEditor({
                   </div>
                 </div>
               )}
+              {(detail.common_context_vars?.length ?? 0) > 0 && (
+                <div>
+                  <p className="mb-1.5 text-xs font-medium text-dark-400">
+                    {t('admin.emailTemplates.variablesCommon')}
+                  </p>
+                  <div className="flex flex-wrap gap-1 sm:gap-1.5">
+                    {detail.common_context_vars!.map((v) => (
+                      <code
+                        key={v}
+                        className="cursor-pointer rounded bg-dark-800 px-2 py-0.5 font-mono text-xs text-dark-300 ring-1 ring-dark-600 transition-colors hover:bg-dark-700 hover:text-accent-400"
+                        title={t('admin.emailTemplates.clickToInsert')}
+                        onClick={() => insertVariable(v)}
+                      >
+                        {`{${v}}`}
+                      </code>
+                    ))}
+                  </div>
+                </div>
+              )}
+            </div>
+          )}
 
           {/* Body HTML editor */}
           <div>