test: add Electron smoke test

[icebear0828]

This pull request introduces a smoke test to ensure the Electron app successfully builds, packages, and launches without crashing, addressing the requirements outlined in #121.

The changes involve:

1. Adding @playwright/test and playwright as development dependencies in the packages/electron workspace.
2. Creating an isolated E2E test packages/electron/__tests__/smoke.test.ts using Vitest and Playwright. The test:
   • Uses esbuild and electron-builder to verify the build process.
   • Launches the compiled executable headless-ly.
   • Verifies the application's main window opens and checks the title.
3. Implementing proper cleanup of transient testing artifacts (temporary Chromium data directory).
4. Restricting the execution of this specific smoke test using describe.runIf to prevent it from polluting standard unit test executions by requiring explicitly set environment variables (CI or RUN_E2E_SMOKE), thus resolving the local DX degradation issue.
5. Successfully bypassing native module (codex-tls) loading errors during testing by generating a temporary local.yaml overlay configuring the curl-cli transport and executing with DISABLE_NATIVE_TRANSPORT=1.

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PR created automatically by Jules for task 17712378451594297203 started by @icebear0828

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