update default model to qwen3:14b across routes, services, and frontend components

src/routes/chats.js

@@ -22,7 +22,7 @@ const sendMessageValidator = (body) => {
     if (!chatId) return {error: "chatId is required"};
     if (!message) return {error: "message is required"};
     if (body.webSearch !== undefined && typeof body.webSearch !== "boolean") return {error: "webSearch must be a boolean"};
-    return {value: {message, chatId, model: String(body?.model || "mistral:latest"), webSearch: body.webSearch === true}};
+    return {value: {message, chatId, model: String(body?.model || "qwen3:14b"), webSearch: body.webSearch === true}};
 };
 
 const organizationValidator = (body) => ({
@@ -478,7 +478,7 @@ export function createChatsRouter({repositories, chatService, modelService, conf
             const result = await chatService.retryMessage({
                 user: req.session.user,
                 chatId,
-                selectedModel: String(req.body?.model || "mistral:latest"),
+                selectedModel: String(req.body?.model || "qwen3:14b"),
                 targetMessage,
                 retryStyle: String(req.body?.style || "").trim() || null
             });
@@ -502,7 +502,7 @@ export function createChatsRouter({repositories, chatService, modelService, conf
             const result = await chatService.retryMessage({
                 user: req.session.user,
                 chatId,
-                selectedModel: String(req.body?.model || "mistral:latest"),
+                selectedModel: String(req.body?.model || "qwen3:14b"),
                 targetMessage,
                 retryStyle: String(req.body?.style || "").trim() || null
             });