fix(desktop): skip WSL distro probing while the WSL backend is off

apps/desktop/src/ipc/methods/wsl.test.ts

@@ -120,6 +120,43 @@ describe("WSL IPC", () => {
     ),
   );
 
+  it.effect("does not enumerate distros until the WSL backend is enabled", () => {
+    const distros = [
+      { name: "Ubuntu", isDefault: true, version: 2 as const },
+      { name: "Debian", isDefault: false, version: 2 as const },
+    ];
+    const layer = Layer.mergeAll(
+      DesktopAppSettings.layerTest({
+        ...DesktopAppSettings.DEFAULT_DESKTOP_SETTINGS,
+        wslDistro: "Debian",
+      }),
+      DesktopWslEnvironment.layerTest({ isAvailable: true, distros }),
+      layerWslBackend(),
+      layerLifecycle([]),
+      layerUnusedLifecycleRuntime,
+    );
+
+    return Effect.gen(function* () {
+      const wsl = yield* DesktopWslEnvironment.DesktopWslEnvironment;
+      const state = yield* getWslState.handler(undefined).pipe(
+        Effect.provideService(DesktopWslEnvironment.DesktopWslEnvironment, {
+          ...wsl,
+          listDistros: Effect.die("must not enumerate distros"),
+        }),
+        Effect.flatMap(decodeWslState),
+      );
+      assert.equal(state.enabled, false);
+      assert.equal(state.available, true);
+      assert.equal(state.distro, "Debian");
+      assert.deepEqual(state.distros, []);
+
+      const enabledState = yield* invokeSetWslBackendEnabled(true);
+      assert.equal(enabledState.enabled, true);
+      assert.equal(enabledState.distro, "Debian");
+      assert.deepEqual(enabledState.distros, distros);
+    }).pipe(Effect.provide(layer));
+  });
+
   it.effect("stages dual-backend preferences before enabling without relaunching", () => {
     const relaunchReasons: Array<string> = [];
     const layer = Layer.mergeAll(

apps/desktop/src/ipc/methods/wsl.ts

@@ -22,9 +22,9 @@ const readWslState: Effect.Effect<
   const wslBackend = yield* DesktopWslBackend.DesktopWslBackend;
   const settings = yield* appSettings.get;
   const available = settings.localEnvironmentEnabled && (yield* wslEnvironment.isAvailable);
-  // Only enumerate distros when WSL is actually available — listDistros on a
-  // non-WSL host would spawn wsl.exe and hit the timeout for nothing.
-  const distros = available ? yield* wslEnvironment.listDistros : [];
+  // Windows ships a wsl.exe stub that can prompt to install WSL when invoked.
+  // Keep disabled state reads from launching it to enumerate distros.
+  const distros = available && settings.wslBackendEnabled ? yield* wslEnvironment.listDistros : [];
   const preflightError = yield* wslBackend.lastPreflightError;
   return {
     enabled: settings.wslBackendEnabled,

apps/web/src/components/settings/ConnectionsSettings.tsx

@@ -3307,9 +3307,16 @@ export function ConnectionsSettings() {
                   Off
                 </SelectItem>
                 {desktopWslState.distros.length === 0 ? (
-                  <SelectItem hideIndicator value={BACKEND_VALUE_DEFAULT_WSL}>
-                    Default distro
-                  </SelectItem>
+                  <>
+                    <SelectItem hideIndicator value={BACKEND_VALUE_DEFAULT_WSL}>
+                      Default distro
+                    </SelectItem>
+                    {desktopWslState.distro !== null ? (
+                      <SelectItem hideIndicator value={desktopWslState.distro}>
+                        {desktopWslState.distro}
+                      </SelectItem>
+                    ) : null}
+                  </>
                 ) : (
                   desktopWslState.distros.map((distro) => (
                     <SelectItem hideIndicator key={distro.name} value={distro.name}>