fix(mcp): use linux local data dir

docs/content/docs/mcp.cn.mdx

@@ -202,7 +202,7 @@ MCP Server 从 DBX 的 SQLite 数据库读取连接信息：
 | 平台    | 路径                                               |
 | ------- | -------------------------------------------------- |
 | macOS   | `~/Library/Application Support/com.dbx.app/dbx.db` |
-| Linux   | `~/.config/com.dbx.app/dbx.db`                     |
+| Linux   | `~/.local/share/com.dbx.app/dbx.db`                |
 | Windows | `%APPDATA%\com.dbx.app\dbx.db`                     |
 
 ### UI 联动

docs/content/docs/mcp.mdx

@@ -202,7 +202,7 @@ The MCP Server reads DBX's SQLite database:
 | Platform | Path                                               |
 | -------- | -------------------------------------------------- |
 | macOS    | `~/Library/Application Support/com.dbx.app/dbx.db` |
-| Linux    | `~/.config/com.dbx.app/dbx.db`                     |
+| Linux    | `~/.local/share/com.dbx.app/dbx.db`                |
 | Windows  | `%APPDATA%\com.dbx.app\dbx.db`                     |
 
 ### UI Integration

packages/mcp-server/README.md

@@ -117,7 +117,7 @@ AI Agent → MCP Server → Database
 The MCP server reads your database connections from DBX's SQLite database:
 
 - **macOS**: `~/Library/Application Support/com.dbx.app/dbx.db`
-- **Linux**: `~/.config/com.dbx.app/dbx.db`
+- **Linux**: `~/.local/share/com.dbx.app/dbx.db`
 - **Windows**: `%APPDATA%\com.dbx.app\dbx.db`
 
 ## DBX UI Integration
@@ -234,7 +234,7 @@ DBX_MCP_ALLOW_DANGEROUS_SQL=1
 MCP Server 从 DBX 的 SQLite 数据库读取连接信息：
 
 - **macOS**: `~/Library/Application Support/com.dbx.app/dbx.db`
-- **Linux**: `~/.config/com.dbx.app/dbx.db`
+- **Linux**: `~/.local/share/com.dbx.app/dbx.db`
 - **Windows**: `%APPDATA%\com.dbx.app\dbx.db`
 
 ### DBX UI 联动

packages/node-core/src/database.ts

@@ -1,11 +1,12 @@
 import type { ConnectionConfig, ProxyTunnelConfig } from "./connections.js";
 import { createServer, connect as netConnect, type Server, type Socket } from "node:net";
 import { readFile } from "node:fs/promises";
+import { homedir } from "node:os";
 import { join } from "node:path";
-import { homedir, platform } from "node:os";
 import Database from "better-sqlite3";
 import { sqlSafetyFromEnv } from "./sql-safety.js";
 import { isDirectQueryType } from "./diagnostics.js";
+import { bridgePortFilePath } from "./paths.js";
 
 export interface TableInfo {
   name: string;
@@ -325,23 +326,10 @@ interface MongoDocumentResult {
   total: number;
 }
 
-function bridgeAppDataDir(): string {
-  const home = homedir();
-  switch (platform()) {
-    case "darwin":
-      return join(home, "Library", "Application Support", "com.dbx.app");
-    case "win32":
-      return join(process.env.APPDATA || join(home, "AppData", "Roaming"), "com.dbx.app");
-    default:
-      return join(home, ".config", "com.dbx.app");
-  }
-}
-
 async function bridgeDataRequest<T>(path: string, body: Record<string, unknown>): Promise<T> {
   let bridgeUrl: string;
   try {
-    const portFile = join(bridgeAppDataDir(), "mcp-bridge-port");
-    const port = (await readFile(portFile, "utf-8")).trim();
+    const port = (await readFile(bridgePortFilePath(), "utf-8")).trim();
     bridgeUrl = `http://127.0.0.1:${port}`;
   } catch {
     throw new Error("DBX desktop app is not running. This database type requires DBX to be running for query execution.");

packages/node-core/src/paths.ts

@@ -3,19 +3,26 @@ import { join } from "node:path";
 
 export function appDataDir(): string {
   // 支持 DBX_DATA_DIR 环境变量（与 Rust 侧 data_dir.rs 保持一致）
-  const envDir = process.env.DBX_DATA_DIR;
-  if (envDir && envDir.trim() !== "") {
-    return envDir;
+  return appDataDirFromInputs({
+    platform: platform(),
+    home: homedir(),
+    appData: process.env.APPDATA,
+    envDataDir: process.env.DBX_DATA_DIR,
+  });
+}
+
+export function appDataDirFromInputs(options: { platform: NodeJS.Platform; home: string; appData?: string; envDataDir?: string }): string {
+  if (options.envDataDir && options.envDataDir.trim() !== "") {
+    return options.envDataDir;
   }
 
-  const home = homedir();
-  switch (platform()) {
+  switch (options.platform) {
     case "darwin":
-      return join(home, "Library", "Application Support", "com.dbx.app");
+      return join(options.home, "Library", "Application Support", "com.dbx.app");
     case "win32":
-      return join(process.env.APPDATA || join(home, "AppData", "Roaming"), "com.dbx.app");
+      return join(options.appData || join(options.home, "AppData", "Roaming"), "com.dbx.app");
     default:
-      return join(home, ".config", "com.dbx.app");
+      return join(options.home, ".local", "share", "com.dbx.app");
   }
 }
 

packages/node-core/tests/paths.test.ts

@@ -0,0 +1,11 @@
+import assert from "node:assert/strict";
+import { test } from "vitest";
+import { appDataDirFromInputs } from "../src/paths.js";
+
+test("default app data dir matches Tauri local data dir on Linux", () => {
+  assert.equal(appDataDirFromInputs({ platform: "linux", home: "/home/dbx" }), "/home/dbx/.local/share/com.dbx.app");
+});
+
+test("DBX_DATA_DIR overrides the default app data dir", () => {
+  assert.equal(appDataDirFromInputs({ platform: "linux", home: "/home/dbx", envDataDir: "/tmp/dbx-data" }), "/tmp/dbx-data");
+});