fix(tabs): use query file icon for query tabs

apps/desktop/src/components/layout/TabModeIcon.vue

@@ -42,6 +42,6 @@ defineProps<{ tab: QueryTab }>();
   <Gauge v-else-if="tab.mode === 'dolt-version-control'" />
   <PluginIcon v-else-if="tab.mode === 'plugin-workbench' && tab.pluginWorkbench" :plugin-id="tab.pluginWorkbench.pluginId" :contribution-id="tab.pluginWorkbench.contributionId" />
   <PluginIcon v-else-if="tab.mode === 'plugin-filesystem' && tab.pluginFilesystem" :plugin-id="tab.pluginFilesystem.pluginId" :contribution-id="tab.pluginFilesystem.providerId" />
-  <DatabaseIcon v-else-if="tab.mode === 'query'" :db-type="tabDatabaseIconType(tab)" />
+  <FileCode v-else-if="tab.mode === 'query'" />
   <Code2 v-else />
 </template>

apps/desktop/src/lib/__tests__/tabs/tabPresentation.spec.ts

@@ -957,6 +957,7 @@ describe("statement execution markers", () => {
 
 describe("shared tab presentation helpers", () => {
   it("classifies tab icon colors without MQ special-casing", () => {
+    expect(tabIconClass(queryTab({}))).toBe("text-blue-400");
     expect(tabIconClass(queryTab({ mode: "data" }))).toContain("text-green-500");
     const connectionStore = useConnectionStore();
     connectionStore.connections = [{ id: "dynamodb-1", name: "DynamoDB", db_type: "dynamodb", driver_profile: "dynamodb", color: "" } as ConnectionConfig];

apps/desktop/src/lib/tabs/tabPresentation.ts

@@ -819,9 +819,8 @@ export function tabIconClass(tab: QueryTab): string {
   if (tab.mode === "mongo") return "text-green-400";
   if (tab.mode === "vector") return "text-cyan-400";
   if (tab.mode === "structure") return "text-blue-500";
-  // query 的图标是数据库品牌 logo（TabModeIcon），不吃文字颜色；回退的
-  // Database 图标自带 text-blue-400，与 mq 模式同样返回空串。
-  if (tab.mode === "query") return "";
+  // Match the saved query file icon in the connection sidebar.
+  if (tab.mode === "query") return "text-blue-400";
   return "text-blue-600 dark:text-blue-400";
 }