fix(schema): auto-select schema when creating query from schema context menu

When right-clicking a PostgreSQL schema node and selecting "New Query",
the schema dropdown in the editor toolbar was not pre-selected. Pass
node.schema to createTab so the editor initializes with the correct schema.

apps/desktop/src/components/sidebar/TreeItem.vue

@@ -561,7 +561,7 @@ async function newQuery() {
     await connectionStore.ensureConnected(node.connectionId);
     connectionStore.activeConnectionId = node.connectionId;
     if (node.database) {
-      queryStore.createTab(node.connectionId, node.database, undefined, "query");
+      queryStore.createTab(node.connectionId, node.database, undefined, "query", node.schema);
       return;
     }
     const connection = connectionStore.getConfig(node.connectionId);

apps/desktop/src/stores/queryStore.ts

@@ -111,7 +111,13 @@ export const useQueryStore = defineStore("query", () => {
     return tabs.value.find((t) => t.connectionId === connectionId && t.database === database && t.title === title);
   }
 
-  function createTab(connectionId: string, database: string, title?: string, mode: QueryTab["mode"] = "query") {
+  function createTab(
+    connectionId: string,
+    database: string,
+    title?: string,
+    mode: QueryTab["mode"] = "query",
+    schema?: string,
+  ) {
     if (title) {
       const existing = findTabByTitle(connectionId, database, title);
       if (existing) {
@@ -126,6 +132,7 @@ export const useQueryStore = defineStore("query", () => {
       title: title || `Query ${tabs.value.length + 1}`,
       connectionId,
       database,
+      schema,
       sql: "",
       isExecuting: false,
       isCancelling: false,