fix(tests): provide localStorage shim in jsdom test setup

[dan-nyanko]

Summary

projectsPersistence.test.ts and projectsSlice.test.ts were failing with TypeError: Cannot read properties of undefined (reading 'getItem') because localStorage was undefined in the test environment. This adds a minimal, guarded in-memory localStorage shim to src/test/setup.ts so tests pass consistently regardless of runtime.

Root cause

The repo's vitest config uses environment: 'jsdom', which normally exposes localStorage. However, on runtimes where jsdom does not reliably expose it (e.g. Node 26's experimental built-in localStorage shadows the jsdom one, emitting localStorage is not available because --localstorage-file was not provided), localStorage ends up undefined, breaking any test that reads/writes project state via localStorage.

Fix

In src/test/setup.ts, detect a missing localStorage and install an in-memory Storage shim on both globalThis and window. The shim is guarded by a typeof check, so it only applies when absent — behavior is unchanged on environments where jsdom already provides localStorage. The existing beforeEach cleanup is preserved.

Testing

• pnpm run test → 61 passed (was 54 passed / 7 failed before the fix)
• pnpm run lint, pnpm run format:check, pnpm run typecheck → all pass

Scope

Single-file change (src/test/setup.ts). No application/runtime code is affected; it only touches the test environment.

[flowdeskadmin]

👍