Add Electron application support

[shenthils-ui]

Thank you for the detailed review — I've addressed every point below.

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What I was trying to do and where I needed help

I implemented the initial Electron integration myself: the proto definition,
the gRPC wiring, the Python keyword skeleton, and getting the test app to launch.
I hit two specific blockers:

1. firstWindow() sometimes returns a short-lived splash screen with no title,
   causing Get Title to fail non-deterministically.
2. Mapping an ElectronApplication into the library's PlaywrightState browser
   stack (so normal page keywords like Click just work) required understanding
   internals of the state machine I had not touched before.

I used Claude (Anthropic) to help resolve both. I've now marked every
AI-assisted section with a comment (see electron.py and
playwright-state.ts) so the RFFoundation copyright in the file headers
does not extend to those parts.

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Addressing each review comment

Generated files (Browser/generated/, Browser/wrapper/index.js,

node/playwright-wrapper/generated/)

Not in this PR. The earlier messy force-push had them; they are gone.

package.json — protoc-gen-js

Also gone. That was from an intermediate commit; our PR does not modify
the root package.json.

executable_path — should be Path not str

Fixed. Type annotation is Path; the value is coerced to str only
at the gRPC boundary.

wait_for_electron_app_ready as a separate keyword

Removed. The wait_until: PageLoadStates parameter on
New Electron Application replaces it. Default is domcontentloaded
so the keyword waits for the page to be ready before returning.

Use Enum for state

PageLoadStates (from Browser.utils.data_types) is used for wait_until.

AI-generated code

Both Browser/keywords/electron.py and the new functions in
node/playwright-wrapper/playwright-state.ts carry a NOTE comment:

# NOTE: This file was written with AI assistance (Claude by Anthropic)
# under the supervision of the contributor. The contributor is the
# copyright holder for this file; the Robot Framework Foundation
# copyright above does not extend to AI-generated code.

Let me know if you'd prefer a different format for that disclosure.

Tests — no skipping, build in CI, source in repo, no committed binary

• No Skip anywhere in the test file.
• The electron app source lives at node/electron-test-app/ (committed JS only).
• Suite Setup runs npm install in that directory so the Electron binary
  is downloaded fresh — no binary committed to the repo.
• This works identically in CI and locally.
• node/electron-test-app/README.md documents how to build and run.

More tests

Added 5 new tests (18 total):

Test	What it covers
Wait For Elements State Works	Playwright's promise-based waitForSelector through gRPC; toggle hidden↔visible
Async Content Appears After Delay	800 ms JS setTimeout → element becomes visible; tests async/promise path
Keyboard Input Works	Fill Text + Ctrl+A + Delete
File Input Accepts A File	Upload File By Selector on a native <input type="file">
Evaluate JavaScript Returns Promise Result	async (el) => { await …; return … } through eval

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Files changed

File	Change
protobuf/playwright.proto	Added ElectronLaunch message and LaunchElectron, CloseElectron, OpenElectronDevTools RPCs
node/playwright-wrapper/grpc-service.ts	Wired the three new RPCs to their handlers
node/playwright-wrapper/playwright-state.ts	Added launchElectron, closeElectron, openElectronDevTools functions + electronApp field on PlaywrightState
Browser/keywords/electron.py	New Electron keyword class: New Electron Application, Close Electron Application, Open Electron Dev Tools
Browser/keywords/__init__.py	Imported Electron mixin
Browser/browser.py	Added Electron to the library class
node/electron-test-app/main.js	Minimal Electron main process (creates BrowserWindow, loads index.html)
node/electron-test-app/index.html	Renderer page: click counter, text input, select, checkbox, toggle, async element, file input
node/electron-test-app/package.json	electron dev dependency
node/electron-test-app/README.md	How to build and run the test app
node/electron-test-app/.gitignore	Ignore node_modules/, *.sock
atest/test/01_Browser_Management/electron.robot	18 acceptance tests
tasks.py	Added electron_test_app_install invoke task