diff --git a/apps/dashboard/src/lib/remote-development-environment/config-file.ts b/apps/dashboard/src/lib/remote-development-environment/config-file.ts
index 1a32d1f76..6725dd735 100644
--- a/apps/dashboard/src/lib/remote-development-environment/config-file.ts
+++ b/apps/dashboard/src/lib/remote-development-environment/config-file.ts
@@ -3,6 +3,7 @@ import "server-only";
 import { showOnboardingHexclaveConfigValue } from "@hexclave/shared/dist/config-authoring";
 import { Config, isValidConfig } from "@hexclave/shared/dist/config/format";
 import { detectImportPackageFromDir, renderConfigFileContent } from "@hexclave/shared/dist/config-rendering";
+import { captureError } from "@hexclave/shared/dist/utils/errors";
 import { createHash } from "crypto";
 import { existsSync, mkdirSync, readFileSync, renameSync, writeFileSync } from "fs";
 import { createJiti } from "jiti";
@@ -66,9 +67,12 @@ export async function readConfigFile(configFilePath: string): Promise<{ config:
   try {
     configModule = await jiti.import<unknown>(configFilePath);
   } catch (error) {
+    // Capture the raw jiti/framework error for diagnostics, but don't attach it as `cause` on the thrown error:
+    // the dashboard's error formatter (errorToNiceString -> nicify) renders `Error.cause` recursively, which would
+    // leak the underlying framework stack/internals back into the user-facing message we're deliberately replacing.
+    captureError("remote-development-environment/readConfigFile", error);
     throw new Error(
       `Failed to load config file ${configFilePath}. If your config imports a value (e.g. defineHexclaveConfig) from a framework package such as "@hexclave/next", import it from that package's lightweight "/config" entrypoint instead, which doesn't load the framework runtime:\n\n  import { defineHexclaveConfig } from "@hexclave/next/config";\n`,
-      { cause: error },
     );
   }
   if (!isConfigModule(configModule)) {
diff --git a/packages/shared/src/config-rendering.ts b/packages/shared/src/config-rendering.ts
index b3581631a..d28cc2588 100644
--- a/packages/shared/src/config-rendering.ts
+++ b/packages/shared/src/config-rendering.ts
@@ -13,6 +13,7 @@ export { parseHexclaveConfigFileContent, renderConfigFileContent };
 const CONFIG_IMPORT_PACKAGES = [
   "@hexclave/next",
   "@hexclave/react",
+  "@hexclave/tanstack-start",
   "@hexclave/js",
   "@hexclave/template",
   "@stackframe/stack",
@@ -139,6 +140,7 @@ import.meta.vitest?.test("detectConfigImportPackage picks first matching package
   expect(detectConfigImportPackage(["@hexclave/next", "@hexclave/js"])).toBe("@hexclave/next");
   expect(detectConfigImportPackage(["@hexclave/react", "@hexclave/js"])).toBe("@hexclave/react");
   expect(detectConfigImportPackage(["@hexclave/js"])).toBe("@hexclave/js");
+  expect(detectConfigImportPackage(["@hexclave/tanstack-start"])).toBe("@hexclave/tanstack-start");
   // Hexclave names take priority over legacy stackframe names when both appear.
   expect(detectConfigImportPackage(["@stackframe/stack", "@hexclave/next"])).toBe("@hexclave/next");
   // Legacy fallback still works for projects pinned to the last @stackframe/* release.