feat(agent-model): add per-agent model override with default-reset UX and runtime sync (#651)

src/i18n/locales/en/agents.json

@@ -30,6 +30,17 @@
         "nameLabel": "Agent Name",
         "agentIdLabel": "Agent ID",
         "modelLabel": "Model",
+        "modelOverrideLabel": "Model Override",
+        "modelProviderLabel": "Provider",
+        "modelProviderPlaceholder": "Select a provider",
+        "modelProviderEmpty": "No provider accounts configured. Add one in Settings → AI Providers.",
+        "modelIdLabel": "Model ID",
+        "modelIdPlaceholder": "model-id",
+        "modelPreview": "Preview",
+        "modelOverridePlaceholder": "provider/model (for example: openrouter/openai/gpt-5.4)",
+        "modelOverrideDescription": "Select provider and model ID for this agent.",
+        "saveModelOverride": "Save model",
+        "useDefaultModel": "Use default model",
         "channelsTitle": "Channels",
         "channelsDescription": "This list is read-only. Manage channel accounts and bindings in the Channels page.",
         "mainAccount": "Main account",
@@ -48,6 +59,13 @@
         "agentDeleteFailed": "Failed to delete agent: {{error}}",
         "agentUpdated": "Agent updated",
         "agentUpdateFailed": "Failed to update agent: {{error}}",
+        "agentModelInvalid": "Model must be in provider/model format",
+        "agentModelProviderRequired": "Select a provider first",
+        "agentModelIdRequired": "Model ID is required",
+        "agentModelUpdated": "Agent model updated",
+        "agentModelUpdateFailed": "Failed to update agent model: {{error}}",
+        "agentModelReset": "Agent model reset to default",
+        "agentModelResetFailed": "Failed to reset agent model: {{error}}",
         "channelAssigned": "{{channel}} assigned to agent",
         "channelAssignFailed": "Failed to assign channel: {{error}}",
         "channelRemoved": "{{channel}} removed",

src/i18n/locales/ja/agents.json

@@ -30,6 +30,17 @@
         "nameLabel": "Agent 名",
         "agentIdLabel": "Agent ID",
         "modelLabel": "Model",
+        "modelOverrideLabel": "モデル上書き",
+        "modelProviderLabel": "Provider",
+        "modelProviderPlaceholder": "Provider を選択",
+        "modelProviderEmpty": "Provider アカウントが未設定です。設定 → AI Providers で追加してください。",
+        "modelIdLabel": "モデル ID",
+        "modelIdPlaceholder": "model-id",
+        "modelPreview": "プレビュー",
+        "modelOverridePlaceholder": "provider/model（例: openrouter/openai/gpt-5.4）",
+        "modelOverrideDescription": "この Agent の Provider とモデル ID を選択します。",
+        "saveModelOverride": "モデルを保存",
+        "useDefaultModel": "デフォルトモデルを使用",
         "channelsTitle": "Channels",
         "channelsDescription": "この一覧は読み取り専用です。チャンネルアカウントと紐付けは Channels ページで管理してください。",
         "mainAccount": "メインアカウント",
@@ -48,6 +59,13 @@
         "agentDeleteFailed": "Agent の削除に失敗しました: {{error}}",
         "agentUpdated": "Agent を更新しました",
         "agentUpdateFailed": "Agent の更新に失敗しました: {{error}}",
+        "agentModelInvalid": "モデル形式は provider/model で指定してください",
+        "agentModelProviderRequired": "先に Provider を選択してください",
+        "agentModelIdRequired": "モデル ID は必須です",
+        "agentModelUpdated": "Agent のモデルを更新しました",
+        "agentModelUpdateFailed": "Agent モデルの更新に失敗しました: {{error}}",
+        "agentModelReset": "Agent モデルをデフォルトに戻しました",
+        "agentModelResetFailed": "Agent モデルのリセットに失敗しました: {{error}}",
         "channelAssigned": "{{channel}} を Agent に割り当てました",
         "channelAssignFailed": "Channel の割り当てに失敗しました: {{error}}",
         "channelRemoved": "{{channel}} を削除しました",

src/i18n/locales/zh/agents.json

@@ -30,6 +30,17 @@
         "nameLabel": "Agent 名称",
         "agentIdLabel": "Agent ID",
         "modelLabel": "Model",
+        "modelOverrideLabel": "模型覆盖",
+        "modelProviderLabel": "Provider",
+        "modelProviderPlaceholder": "选择 Provider",
+        "modelProviderEmpty": "尚未配置 Provider 账号。请先前往 设置 → AI Providers 添加。",
+        "modelIdLabel": "模型 ID",
+        "modelIdPlaceholder": "model-id",
+        "modelPreview": "预览",
+        "modelOverridePlaceholder": "provider/model（例如：openrouter/openai/gpt-5.4）",
+        "modelOverrideDescription": "为该 Agent 选择 Provider 和模型 ID。",
+        "saveModelOverride": "保存模型",
+        "useDefaultModel": "使用默认模型",
         "channelsTitle": "频道",
         "channelsDescription": "该列表为只读。频道账号与绑定关系请在 Channels 页面管理。",
         "mainAccount": "主账号",
@@ -48,6 +59,13 @@
         "agentDeleteFailed": "删除 Agent 失败：{{error}}",
         "agentUpdated": "Agent 已更新",
         "agentUpdateFailed": "更新 Agent 失败：{{error}}",
+        "agentModelInvalid": "模型格式必须为 provider/model",
+        "agentModelProviderRequired": "请先选择 Provider",
+        "agentModelIdRequired": "模型 ID 不能为空",
+        "agentModelUpdated": "Agent 模型已更新",
+        "agentModelUpdateFailed": "更新 Agent 模型失败：{{error}}",
+        "agentModelReset": "Agent 模型已恢复为默认",
+        "agentModelResetFailed": "恢复 Agent 默认模型失败：{{error}}",
         "channelAssigned": "{{channel}} 已分配给 Agent",
         "channelAssignFailed": "分配频道失败：{{error}}",
         "channelRemoved": "{{channel}} 已移除",