🌐 i18n(combos): add internationalization support for agent features section

- replace hardcoded english text with translation keys in combo form modal
- add english and chinese translations for agent features labels and descriptions
- include system message override, tool filter regex, and context cache protection strings

📝 docs(translations): update i18n message files with new agent features entries

- add agentFeaturesTitle, agentFeaturesDescription, agentFeaturesSystemMessageOverride
- add agentFeaturesSystemMessagePlaceholder, agentFeaturesSystemMessageHint
- add agentFeaturesToolFilterRegex, agentFeaturesToolFilterHint
- add agentFeaturesContextCacheProtection, agentFeaturesContextCacheHint

src/app/(dashboard)/dashboard/combos/page.tsx

@@ -3388,34 +3388,31 @@ function ComboFormModal({ isOpen, combo, onClose, onSave, activeProviders }) {
                 <span className="material-symbols-outlined text-[14px] text-primary">
                   smart_toy
                 </span>
-                <p className="text-xs font-medium">Agent Features</p>
-                <span className="text-[10px] text-text-muted">
-                  — optional, for agent/tool workflows
-                </span>
+                <p className="text-xs font-medium">{t("agentFeaturesTitle")}</p>
+                <span className="text-[10px] text-text-muted">{t("agentFeaturesDescription")}</span>
               </div>
 
               {/* System Message Override */}
               <div>
                 <label className="text-[11px] font-medium text-text-muted block mb-0.5">
-                  System Message Override
+                  {t("agentFeaturesSystemMessageOverride")}
                 </label>
                 <textarea
                   rows={2}
                   value={agentSystemMessage}
                   onChange={(e) => setAgentSystemMessage(e.target.value)}
-                  placeholder="Override the system prompt for all requests routed through this combo…"
+                  placeholder={t("agentFeaturesSystemMessagePlaceholder")}
                   className="w-full text-xs py-1.5 px-2 rounded border border-black/10 dark:border-white/10 bg-transparent focus:border-primary focus:outline-none resize-none"
                 />
                 <p className="text-[10px] text-text-muted mt-0.5">
-                  Replaces any system message sent by the client. Leave empty to pass through client
-                  system messages.
+                  {t("agentFeaturesSystemMessageHint")}
                 </p>
               </div>
 
               {/* Tool Filter Regex */}
               <div>
                 <label className="text-[11px] font-medium text-text-muted block mb-0.5">
-                  Tool Filter Regex
+                  {t("agentFeaturesToolFilterRegex")}
                 </label>
                 <input
                   type="text"
@@ -3425,8 +3422,7 @@ function ComboFormModal({ isOpen, combo, onClose, onSave, activeProviders }) {
                   className="w-full text-xs py-1.5 px-2 rounded border border-black/10 dark:border-white/10 bg-transparent focus:border-primary focus:outline-none font-mono"
                 />
                 <p className="text-[10px] text-text-muted mt-0.5">
-                  Only tools whose name matches this regex are forwarded to the provider. Leave
-                  empty to forward all tools.
+                  {t("agentFeaturesToolFilterHint")}
                 </p>
               </div>
 
@@ -3434,11 +3430,10 @@ function ComboFormModal({ isOpen, combo, onClose, onSave, activeProviders }) {
               <div className="flex items-center justify-between gap-2">
                 <div>
                   <label className="text-[11px] font-medium text-text-muted block">
-                    Context Cache Protection
+                    {t("agentFeaturesContextCacheProtection")}
                   </label>
                   <p className="text-[10px] text-text-muted">
-                    Pins the provider/model across turns to preserve cache sessions. Internal tags
-                    are stripped before forwarding to the provider.
+                    {t("agentFeaturesContextCacheHint")}
                   </p>
                 </div>
                 <input

src/i18n/messages/en.json

@@ -1102,7 +1102,16 @@
     "reviewAdvanced": "Advanced Settings",
     "reviewAgentFlags": "Agent Flags",
     "reviewSequence": "Model Sequence",
-    "reviewNoSteps": "No steps configured"
+    "reviewNoSteps": "No steps configured",
+    "agentFeaturesTitle": "Agent Features",
+    "agentFeaturesDescription": "— optional, for agent/tool workflows",
+    "agentFeaturesSystemMessageOverride": "System Message Override",
+    "agentFeaturesSystemMessagePlaceholder": "Override the system prompt for all requests routed through this combo…",
+    "agentFeaturesSystemMessageHint": "Replaces any system message sent by the client. Leave empty to pass through client system messages.",
+    "agentFeaturesToolFilterRegex": "Tool Filter Regex",
+    "agentFeaturesToolFilterHint": "Only tools whose name matches this regex are forwarded to the provider. Leave empty to forward all tools.",
+    "agentFeaturesContextCacheProtection": "Context Cache Protection",
+    "agentFeaturesContextCacheHint": "Pins the provider/model across turns to preserve cache sessions. Internal tags are stripped before forwarding to the provider."
   },
   "costs": {
     "title": "Costs",

src/i18n/messages/zh-CN.json

@@ -1101,7 +1101,16 @@
     "reviewAdvanced": "高级设置",
     "reviewAgentFlags": "Agent 标志",
     "reviewSequence": "模型序列",
-    "reviewNoSteps": "未配置任何步骤"
+    "reviewNoSteps": "未配置任何步骤",
+    "agentFeaturesTitle": "智能代理功能",
+    "agentFeaturesDescription": "— 可选，用于智能体/工具工作流",
+    "agentFeaturesSystemMessageOverride": "系统消息覆盖",
+    "agentFeaturesSystemMessagePlaceholder": "覆盖通过此组合路由的所有请求的系统提示…",
+    "agentFeaturesSystemMessageHint": "替换客户端发送的任何系统消息。留空则透传客户端系统消息。",
+    "agentFeaturesToolFilterRegex": "工具过滤器正则",
+    "agentFeaturesToolFilterHint": "只有名称匹配此正则的工具才会转发给供应商。留空则转发所有工具。",
+    "agentFeaturesContextCacheProtection": "上下文缓存保护",
+    "agentFeaturesContextCacheHint": "跨轮次锁定供应商/模型以保持缓存会话。内部标签在转发给供应商前会被移除。"
   },
   "costs": {
     "title": "成本",