fix(i18n): add missing translations for reasoning model and OpenRouter compat mode

Add missing i18n keys introduced in commit e6f18ba:
- providerForm.anthropicReasoningModel
- providerForm.reasoningModelPlaceholder
- providerForm.openrouterCompatMode
- providerForm.openrouterCompatModeHint
- proxy.failover.proxyRequired

src/i18n/locales/en.json

@@ -340,6 +340,10 @@
     "visitWebsite": "Visit {{url}}",
     "anthropicModel": "Main Model",
     "anthropicSmallFastModel": "Fast Model",
+    "anthropicReasoningModel": "Reasoning Model (Thinking)",
+    "reasoningModelPlaceholder": "e.g. claude-sonnet-4-20250514",
+    "openrouterCompatMode": "OpenRouter Compatibility Mode",
+    "openrouterCompatModeHint": "Use OpenAI Chat Completions interface and convert to Anthropic SSE.",
     "anthropicDefaultHaikuModel": "Default Haiku Model",
     "anthropicDefaultSonnetModel": "Default Sonnet Model",
     "anthropicDefaultOpusModel": "Default Opus Model",
@@ -1057,6 +1061,9 @@
       }
     },
     "switchFailed": "Switch failed: {{error}}",
+    "failover": {
+      "proxyRequired": "Proxy service must be started to configure failover"
+    },
     "failoverQueue": {
       "title": "Failover Queue",
       "description": "Manage failover order for each app's providers",

src/i18n/locales/ja.json

@@ -340,6 +340,10 @@
     "visitWebsite": "{{url}} を開く",
     "anthropicModel": "メインモデル",
     "anthropicSmallFastModel": "高速モデル",
+    "anthropicReasoningModel": "推論モデル（Thinking）",
+    "reasoningModelPlaceholder": "例: claude-sonnet-4-20250514",
+    "openrouterCompatMode": "OpenRouter 互換モード",
+    "openrouterCompatModeHint": "OpenAI Chat Completions インターフェースを使用し、Anthropic SSE に変換します。",
     "anthropicDefaultHaikuModel": "既定 Haiku モデル",
     "anthropicDefaultSonnetModel": "既定 Sonnet モデル",
     "anthropicDefaultOpusModel": "既定 Opus モデル",
@@ -1057,6 +1061,9 @@
       }
     },
     "switchFailed": "切り替えに失敗しました: {{error}}",
+    "failover": {
+      "proxyRequired": "フェイルオーバーを設定するには、プロキシサービスを先に起動する必要があります"
+    },
     "failoverQueue": {
       "title": "フェイルオーバーキュー",
       "description": "各アプリのプロバイダーのフェイルオーバー順序を管理します",

src/i18n/locales/zh.json

@@ -340,6 +340,10 @@
     "visitWebsite": "访问 {{url}}",
     "anthropicModel": "主模型",
     "anthropicSmallFastModel": "快速模型",
+    "anthropicReasoningModel": "推理模型 (Thinking)",
+    "reasoningModelPlaceholder": "如 claude-sonnet-4-20250514",
+    "openrouterCompatMode": "OpenRouter 兼容模式",
+    "openrouterCompatModeHint": "使用 OpenAI Chat Completions 接口并转换为 Anthropic SSE。",
     "anthropicDefaultHaikuModel": "Haiku 默认模型",
     "anthropicDefaultSonnetModel": "Sonnet 默认模型",
     "anthropicDefaultOpusModel": "Opus 默认模型",
@@ -1057,6 +1061,9 @@
       }
     },
     "switchFailed": "切换失败: {{error}}",
+    "failover": {
+      "proxyRequired": "需要先启动代理服务才能配置故障转移"
+    },
     "failoverQueue": {
       "title": "故障转移队列",
       "description": "管理各应用的供应商故障转移顺序",