fix(duckdb): restore parquet preview and reclaim connections

apps/desktop/src/composables/useFileDrop.ts

@@ -60,8 +60,15 @@ export function useFileDrop() {
               port: 0,
               username: "",
               password: "",
+              one_time: true,
             };
-            const connectionId = await api.connectDb(config);
+            let connectionId: string;
+            try {
+              connectionId = await api.connectDb(config);
+            } catch (e: any) {
+              toast(t("welcome.fileOpenFailed", { name, message: e?.message || String(e) }), 5000);
+              continue;
+            }
             connectionStore.addEphemeralConnection({ ...config, id: connectionId });
             const tabId = queryStore.createTab(connectionId, "", name, "query");
             queryStore.updateSql(tabId, dataQuery);

apps/desktop/src/i18n/locales/en.ts

@@ -2033,6 +2033,7 @@ export default {
     tipSidebar: "Click a table on the left to view data",
     tipExecute: "to execute query",
     fileOpened: "Opened {name}",
+    fileOpenFailed: "Failed to open {name}: {message}",
     mcpTitle: "AI Agent Integration",
     mcpDescription: "Beyond the built-in AI assistant, you can also use Claude Code, Cursor, and other coding agents to query your databases via MCP.",
     mcpLearnMore: "Learn more",

apps/desktop/src/i18n/locales/es.ts

@@ -1967,6 +1967,7 @@ export default withEnglishFallback({
     tipSidebar: "Haz clic en una tabla a la izquierda para ver los datos",
     tipExecute: "para ejecutar la consulta",
     fileOpened: "Abierto {name}",
+    fileOpenFailed: "No se pudo abrir {name}: {message}",
     mcpTitle: "Integración con agentes de IA",
     mcpDescription: "Además del asistente de IA integrado, puedes usar Claude Code, Cursor y otros agentes de programación para consultar tus bases de datos mediante MCP.",
     mcpLearnMore: "Más información",

apps/desktop/src/i18n/locales/it.ts

@@ -1965,6 +1965,7 @@ export default withEnglishFallback({
     tipSidebar: "Fai clic su una tabella a sinistra per visualizzarne i dati",
     tipExecute: "per eseguire la query",
     fileOpened: "Aperto {name}",
+    fileOpenFailed: "Impossibile aprire {name}: {message}",
     mcpTitle: "Integrazione Agente AI",
     mcpDescription: "Oltre all'assistente AI integrato, puoi utilizzare Claude Code, Cursor e altri agenti di sviluppo per interrogare i tuoi database tramite MCP.",
     mcpLearnMore: "Scopri di più",

apps/desktop/src/i18n/locales/ja.ts

@@ -1992,6 +1992,7 @@ export default withEnglishFallback({
     tipSidebar: "左側のテーブルをクリックしてデータを表示",
     tipExecute: "でクエリを実行",
     fileOpened: "{name} を開きました",
+    fileOpenFailed: "{name} を開けませんでした：{message}",
     mcpTitle: "AIエージェント連携",
     mcpDescription: "内蔵AIアシスタントに加えて、Claude Code、Cursor、その他のコーディングエージェントをMCP経由でデータベースクエリに使用できます。",
     mcpLearnMore: "詳細を見る",

apps/desktop/src/i18n/locales/ko.ts

@@ -1894,6 +1894,7 @@ export default withEnglishFallback({
     tipSidebar: "데이터를 보려면 왼쪽의 테이블을 클릭하세요",
     tipExecute: "쿼리를 실행하려면",
     fileOpened: "{name}을(를) 열었습니다",
+    fileOpenFailed: "{name}을(를) 열지 못했습니다: {message}",
     mcpTitle: "AI 에이전트 연동",
     mcpDescription: "내장된 AI 어시스턴트 외에도 Claude Code, Cursor 등의 코딩 에이전트를 MCP로 연결하여 데이터베이스를 쿼리할 수 있습니다.",
     mcpLearnMore: "더 알아보기",

apps/desktop/src/i18n/locales/pt-BR.ts

@@ -1967,6 +1967,7 @@ export default withEnglishFallback({
     tipSidebar: "Clique em uma tabela à esquerda para visualizar os dados",
     tipExecute: "para executar a consulta",
     fileOpened: "{name} aberto",
+    fileOpenFailed: "Falha ao abrir {name}: {message}",
     mcpTitle: "Integração com Agente de IA",
     mcpDescription: "Além do assistente de IA integrado, você também pode usar Claude Code, Cursor e outros agentes de codificação para consultar seus bancos de dados via MCP.",
     mcpLearnMore: "Saiba mais",

apps/desktop/src/i18n/locales/zh-CN.ts

@@ -1957,6 +1957,7 @@ export default withEnglishFallback({
     tipSidebar: "点击左侧表名查看数据",
     tipExecute: "执行查询",
     fileOpened: "已打开 {name}",
+    fileOpenFailed: "打开 {name} 失败：{message}",
     mcpTitle: "AI 编程助手集成",
     mcpDescription: "除了内置 AI 助手，还可以通过 MCP 让 Claude Code、Cursor 等编程助手直接使用这里的数据库连接。",
     mcpLearnMore: "了解更多",

apps/desktop/src/i18n/locales/zh-TW.ts

@@ -1966,6 +1966,7 @@ export default withEnglishFallback({
     tipSidebar: "點選左側資料表以檢視資料",
     tipExecute: "執行查詢",
     fileOpened: "已開啟 {name}",
+    fileOpenFailed: "開啟 {name} 失敗：{message}",
     mcpTitle: "AI 程式設計助理整合",
     mcpDescription: "除了內建 AI 助理，也可以藉由 MCP 讓 Claude Code、Cursor 等程式設計助理查詢你的資料庫。",
     mcpLearnMore: "了解更多",

apps/desktop/src/stores/__tests__/connectionStore.oneTimeCleanup.spec.ts

@@ -0,0 +1,122 @@
+import { createPinia, setActivePinia } from "pinia";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import type { ConnectionConfig } from "@/types/database";
+
+function installLocalStorage() {
+  const data = new Map<string, string>();
+  vi.stubGlobal("localStorage", {
+    getItem: vi.fn((key: string) => data.get(key) ?? null),
+    setItem: vi.fn((key: string, value: string) => data.set(key, value)),
+    removeItem: vi.fn((key: string) => data.delete(key)),
+  });
+}
+
+function installApiMocks() {
+  vi.doMock("@/lib/backend/tauriRuntime", () => ({ isTauriRuntime: () => false }));
+  vi.doMock("@/lib/backend/api", () => ({
+    checkConnectionHealth: vi.fn().mockResolvedValue(undefined),
+    connectDb: vi.fn().mockResolvedValue("preview-1"),
+    disconnectDb: vi.fn().mockResolvedValue(undefined),
+    deleteSchemaCachePrefix: vi.fn().mockResolvedValue(undefined),
+    loadSchemaCache: vi.fn().mockResolvedValue(null),
+    saveConnections: vi.fn().mockResolvedValue(undefined),
+    saveSidebarLayout: vi.fn().mockResolvedValue(undefined),
+    connectionDatabaseInfo: vi.fn().mockResolvedValue(undefined),
+    listInstalledAgents: vi.fn().mockResolvedValue([]),
+    sessionCredentialStatus: vi.fn().mockResolvedValue(false),
+    forgetSessionCredential: vi.fn().mockResolvedValue(undefined),
+  }));
+  // Result-snapshot cleanup hits a relative URL, which node's fetch rejects outright.
+  // Unrelated to what these cases assert.
+  vi.doMock("@/lib/tabs/tabResultCache", async (importOriginal) => {
+    const actual = await importOriginal<typeof import("@/lib/tabs/tabResultCache")>();
+    return { ...actual, deleteTabResultSnapshotsForOwner: vi.fn().mockResolvedValue(undefined) };
+  });
+}
+
+function previewConnection(overrides: Partial<ConnectionConfig> = {}): ConnectionConfig {
+  return {
+    id: "preview-1",
+    name: "[Preview] sales.parquet",
+    db_type: "duckdb",
+    host: ":memory:",
+    port: 0,
+    username: "",
+    password: "",
+    one_time: true,
+    ...overrides,
+  } as ConnectionConfig;
+}
+
+describe("connectionStore one_time runtime cleanup", () => {
+  beforeEach(() => {
+    vi.resetModules();
+    vi.unstubAllGlobals();
+    installLocalStorage();
+    setActivePinia(createPinia());
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  // One-time connections are never persisted, so the backend's save_connections
+  // sync never reclaims them; disconnect_db is the only reclaim point, which makes
+  // an explicit disconnect on removal mandatory.
+  it("removeConnection disconnects a one_time connection so the backend can reclaim it", async () => {
+    installApiMocks();
+    const { useConnectionStore } = await import("@/stores/connectionStore");
+    const store = useConnectionStore();
+    store.connections = [previewConnection()];
+
+    await store.removeConnection("preview-1");
+
+    const { disconnectDb } = await import("@/lib/backend/api");
+    // No clientAttempt: removal is terminal, so a superseded attempt number must not
+    // skip the cleanup.
+    expect(disconnectDb).toHaveBeenCalledWith("preview-1");
+  });
+
+  it("removeConnection leaves saved connections to the save_connections sync", async () => {
+    installApiMocks();
+    const { useConnectionStore } = await import("@/stores/connectionStore");
+    const store = useConnectionStore();
+    store.connections = [previewConnection({ id: "saved-1", one_time: false })];
+
+    await store.removeConnection("saved-1");
+
+    const { disconnectDb } = await import("@/lib/backend/api");
+    expect(disconnectDb).not.toHaveBeenCalled();
+  });
+
+  // The connection is gone for good, so its tabs can never reconnect: executing in
+  // one would fail with "Connection config not found".
+  it("removeConnection closes the tabs of a one_time connection", async () => {
+    installApiMocks();
+    const { useConnectionStore } = await import("@/stores/connectionStore");
+    const { useQueryStore } = await import("@/stores/queryStore");
+    const store = useConnectionStore();
+    const queryStore = useQueryStore();
+    store.connections = [previewConnection()];
+    queryStore.createTab("preview-1", "", "sales.parquet", "query");
+    expect(queryStore.tabs.some((tab) => tab.connectionId === "preview-1")).toBe(true);
+
+    await store.removeConnection("preview-1");
+
+    expect(queryStore.tabs.some((tab) => tab.connectionId === "preview-1")).toBe(false);
+  });
+
+  it("removeConnection keeps the tabs of a saved connection for the disconnect handling mode", async () => {
+    installApiMocks();
+    const { useConnectionStore } = await import("@/stores/connectionStore");
+    const { useQueryStore } = await import("@/stores/queryStore");
+    const store = useConnectionStore();
+    const queryStore = useQueryStore();
+    store.connections = [previewConnection({ id: "saved-1", one_time: false })];
+    queryStore.createTab("saved-1", "", "query.sql", "query");
+
+    await store.removeConnection("saved-1");
+
+    expect(queryStore.tabs.some((tab) => tab.connectionId === "saved-1")).toBe(true);
+  });
+});

apps/desktop/src/stores/connectionStore.ts

@@ -711,6 +711,44 @@ export const useConnectionStore = defineStore("connection", () => {
     return trackDisconnectRequest(connectionId, request, clientAttempt != null);
   }
 
+  /**
+   * One-time connections are never persisted, so the backend's "not in the saved
+   * list, so reclaim it" branch in `sync_connection_configs` never fires for them
+   * (see dbx-core `should_retain_runtime_config`) and `disconnect_db` is the only
+   * reclaim point. Removing one must disconnect it explicitly, or its runtime
+   * config, pool, and tunnel live until the process exits.
+   *
+   * `clientAttempt` is deliberately omitted: removal is terminal, so a superseded
+   * attempt number must not skip the cleanup.
+   */
+  function releaseOneTimeRuntimeConnections(connectionIds: string[]) {
+    for (const connectionId of connectionIds) {
+      let request: Promise<void>;
+      try {
+        request = api.disconnectDb(connectionId);
+      } catch (error) {
+        request = Promise.reject(error);
+      }
+      void trackDisconnectRequest(connectionId, request, false).catch(() => {});
+    }
+  }
+
+  /**
+   * A one-time connection is deleted outright rather than left behind for a
+   * reconnect, so its tabs have nothing to point at once it is gone: executing in
+   * one would fail with "Connection config not found". Close them regardless of
+   * `disconnectTabHandlingMode`, which only makes sense for connections that can
+   * still be reconnected.
+   */
+  async function closeOneTimeConnectionTabs(connectionIds: string[]) {
+    if (!connectionIds.length) return;
+    const { useQueryStore } = await import("@/stores/queryStore");
+    const queryStore = useQueryStore();
+    for (const connectionId of connectionIds) {
+      queryStore.closeConnectionTabs(connectionId);
+    }
+  }
+
   function cancelDisconnectKey(connectionId: string, attempt: number): string {
     return `${connectionId}:${attempt}`;
   }
@@ -2700,8 +2738,11 @@ export const useConnectionStore = defineStore("connection", () => {
     if (!connectionIds.length) return;
 
     const removedIds = new Set(connectionIds);
+    const oneTimeIds = connectionIds.filter((id) => getConfig(id)?.one_time === true);
     const nextConnections = connections.value.filter((c) => !removedIds.has(c.id));
     await persistConnections(nextConnections);
+    await closeOneTimeConnectionTabs(oneTimeIds);
+    releaseOneTimeRuntimeConnections(oneTimeIds);
     await persistTimeoutInheritanceIds(
       settingsStore.editorSettings.connectTimeoutInheritConnectionIds.filter((id) => !removedIds.has(id)),
       settingsStore.editorSettings.queryTimeoutInheritConnectionIds.filter((id) => !removedIds.has(id)),