fix(frontend): remove unused MSW browser worker (#6859)

The frontend uses MSW only through its Node test interceptor, but the unused browser worker requires synchronization after dependency updates and currently breaks make verify.

Remove the unused asset, worker-directory configuration, and freshness checks while preserving Node MSW tests and the separate PWA worker. Update tooling descriptions to match.

Fixes #6858

.github/claude/issue-analyst-context.md

@@ -152,7 +152,7 @@ It is paths-filtered, so a docs-only or workflow-only change produces no run.
 | `golangci` | `golangci-lint` |
 | `fuzz-smoke` | 30s each on `FuzzParseLink` and `FuzzDecodeCertPin` |
 | `codegen` | `npm run gen` then `git diff --exit-code` on the generated files |
-| `frontend` | MSW worker drift, lint, format:check, typecheck, `npm test` (Vitest + headless-Chromium Storybook), build, build-storybook, `npm audit` |
+| `frontend` | lint, format:check, typecheck, `npm test` (Vitest + headless-Chromium Storybook), build, build-storybook, `npm audit` |
 
 **What CI does NOT prove.** These test families `t.Skip` unless an environment
 variable is set, and CI sets only the PostgreSQL ones above:

.github/workflows/ci.yml

@@ -201,9 +201,6 @@ jobs:
       - name: Install
         run: npm ci
         working-directory: frontend
-      - name: Verify generated MSW worker is current
-        run: git diff --exit-code -- public/mockServiceWorker.js package-lock.json
-        working-directory: frontend
       - name: Lint
         run: npm run lint
         working-directory: frontend