feat: add multi-provider model configuration

- Add model config dialog for managing multiple AI providers
- Support for OpenAI, Anthropic, Google, Azure, Bedrock, OpenRouter, DeepSeek, SiliconFlow, Ollama, and AI Gateway
- Add model selector dropdown in chat panel header
- Add API key validation endpoint
- Add custom model ID input with keyboard navigation
- Fix hover highlight in Command component
- Add suggested models for each provider including latest Claude 4.5 series
- Store configuration locally in browser

lib/i18n/dictionaries/en.json

@@ -180,5 +180,24 @@
         "seekingSponsorship": "Call for Sponsorship",
         "contactMe": "Contact Me",
         "usageNotice": "Due to high usage, I have changed the model from Claude to minimax-m2 and added some usage limits. See About page for details."
+    },
+    "modelConfig": {
+        "title": "AI Model Configuration",
+        "description": "Configure multiple AI providers and models",
+        "configure": "Configure",
+        "addProvider": "Add Provider",
+        "addModel": "Add Model",
+        "modelId": "Model ID",
+        "modelLabel": "Display Label",
+        "streaming": "Enable Streaming",
+        "deleteProvider": "Delete Provider",
+        "deleteModel": "Delete Model",
+        "noModels": "No models configured. Add a model to get started.",
+        "selectProvider": "Select a provider or add a new one",
+        "configureMultiple": "Configure multiple AI providers and switch between them easily",
+        "apiKeyStored": "API keys are stored locally in your browser",
+        "test": "Test",
+        "validationError": "Validation failed",
+        "addModelFirst": "Add at least one model to validate"
     }
 }

lib/i18n/dictionaries/ja.json

@@ -180,5 +180,24 @@
         "seekingSponsorship": "スポンサー募集",
         "contactMe": "お問い合わせ",
         "usageNotice": "利用量の増加に伴い、コスト削減のためモデルを Claude から minimax-m2 に変更し、いくつかの利用制限を設けました。詳細は概要ページをご覧ください。"
+    },
+    "modelConfig": {
+        "title": "AIモデル設定",
+        "description": "複数のAIプロバイダーとモデルを設定",
+        "configure": "設定",
+        "addProvider": "プロバイダーを追加",
+        "addModel": "モデルを追加",
+        "modelId": "モデルID",
+        "modelLabel": "表示名",
+        "streaming": "ストリーミングを有効",
+        "deleteProvider": "プロバイダーを削除",
+        "deleteModel": "モデルを削除",
+        "noModels": "モデルが設定されていません。モデルを追加してください。",
+        "selectProvider": "プロバイダーを選択または追加してください",
+        "configureMultiple": "複数のAIプロバイダーを設定して簡単に切り替え",
+        "apiKeyStored": "APIキーはブラウザにローカル保存されます",
+        "test": "テスト",
+        "validationError": "検証に失敗しました",
+        "addModelFirst": "検証するには少なくとも1つのモデルを追加してください"
     }
 }

lib/i18n/dictionaries/zh.json

@@ -180,5 +180,24 @@
         "seekingSponsorship": "寻求赞助（求大佬捞一把）",
         "contactMe": "联系我",
         "usageNotice": "由于使用量过高，我已将模型从 Claude 更换为 minimax-m2，并设置了一些用量限制。详情请查看关于页面。"
+    },
+    "modelConfig": {
+        "title": "AI 模型配置",
+        "description": "配置多个 AI 提供商和模型",
+        "configure": "配置",
+        "addProvider": "添加提供商",
+        "addModel": "添加模型",
+        "modelId": "模型 ID",
+        "modelLabel": "显示名称",
+        "streaming": "启用流式输出",
+        "deleteProvider": "删除提供商",
+        "deleteModel": "删除模型",
+        "noModels": "尚未配置模型。添加模型以开始使用。",
+        "selectProvider": "选择一个提供商或添加新的",
+        "configureMultiple": "配置多个 AI 提供商并轻松切换",
+        "apiKeyStored": "API 密钥存储在您的浏览器本地",
+        "test": "测试",
+        "validationError": "验证失败",
+        "addModelFirst": "请先添加至少一个模型以进行验证"
     }
 }