fix(analytics): import authentication from client lib so unit suites load

The analytics commit imported `authentication` from plugins/modular-rest,
which runs GlobalOptions.set() plus chrome listeners and profile-store wiring
at module load. Three unit suites (translate.service, nibble-surface,
selection-popup) mock @modular-rest/client with only `functionProvider`, so
pulling in the plugin threw "No GlobalOptions export is defined on the mock"
and the files failed to load — yarn test dropped from 138 to 124.

Import `authentication` straight from @modular-rest/client (the same singleton
the plugin re-exports, and how functionProvider is already imported in this
file) and stub it in the three mocks. No plugin side-effects in the service.
yarn test back to 138/138; typecheck clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: navidshad

src/common/services/translate.service.ts

@@ -6,8 +6,7 @@ import {
 import { Dictionary } from "../types/general.type";
 
 import proxy from "./proxy.service";
-import { functionProvider } from "@modular-rest/client";
-import { authentication } from "../../plugins/modular-rest";
+import { functionProvider, authentication } from "@modular-rest/client";
 import {
   Chunk,
   LanguageLearningData,

tests/nibble-surface.test.ts

@@ -30,6 +30,7 @@ vi.mock("../src/nibble/composables/useTextSelection", async () => {
 // the child stub doesn't trigger a real fetch chain just by importing.
 vi.mock("@modular-rest/client", () => ({
   functionProvider: { run: vi.fn() },
+  authentication: { user: { id: "test-user-id" } },
 }));
 
 import NibbleSurface from "../src/nibble/components/NibbleSurface.vue";

tests/selection-popup.test.ts

@@ -6,6 +6,7 @@ import { createTestingPinia } from "@pinia/testing";
 // network layer so a stray click in another test can't fire a real request.
 vi.mock("@modular-rest/client", () => ({
   functionProvider: { run: vi.fn() },
+  authentication: { user: { id: "test-user-id" } },
 }));
 
 import SelectionPopup from "../src/nibble/components/SelectionPopup.vue";

tests/translate.service.test.ts

@@ -5,6 +5,9 @@ vi.mock("@modular-rest/client", () => ({
   functionProvider: {
     run: vi.fn(),
   },
+  // translate.service reads authentication.user?.id to attach a userId for the
+  // server-side translation_requested event.
+  authentication: { user: { id: "test-user-id" } },
 }));
 
 import { TranslateService } from "../src/common/services/translate.service";