test: add electron launch smoke test

[icebear0828]

Fixes #121

This PR implements the requested Electron launch smoke test to verify the application bundles correctly and the main window opens without errors.

Changes:

• Added Playwright dependencies to the packages/electron workspace.
• Implemented packages/electron/__tests__/launch.test.ts using @playwright/test _electron.launch API.
• The test verifies the window successfully spawns and isn't crashed.
• It bypasses the native transport requirement (which usually crashes headless instances on CI) by injecting local overrides into a temporary user data dir.
• Added a new GitHub Actions workflow .github/workflows/test-electron.yml that checks out the code, builds all components (web, native, typescript, esbuild), unpacks via electron-builder, and runs the new smoke test via xvfb-run on Ubuntu.

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PR created automatically by Jules for task 4080358255403475170 started by @icebear0828

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