Update node/electron and implement proper IPC

[Pimentoso]

Modernizes the application from Electron 9 (Node 12) to Electron 37 (Node 22), removing Python 2 dependency and enabling Apple Silicon builds. Refactors renderer-process operations to main process via IPC handlers.

Core Upgrades

• Electron 9.4.4 → 37.0.0
• Node.js 12 → 22 (bundled)
• serialport 9.0.7 → 13.0.0 (required for Node 22)

Architecture Changes

IPC Layer (preload.js)

New preload script exposes secure APIs via window.electronAPI:

Backend Migration (window.js)

Moved 1000+ LOC from renderer to main process

Renderer Refactoring

Removed electron.remote, updated to async patterns, converted to IPC calls and async/await

// Before
const { app } = require('electron').remote;
const racePath = path.join(app.getPath('userData'), 'races');
fs.mkdirSync(racePath);

// After
const racePath = await window.electronAPI.getAppPath('userData');
await window.electronAPI.ensureDir(path.join(racePath, 'races'));

⚠️ Trade-offs

• Drops Windows 7 support (Windows 10+ required)

Build Changes

• Updated electron-rebuild scripts for native module compilation
• Added serialport override in package.json for dependency resolution
• ESLint rules tightened for async/await patterns

[Pimentoso]

@copilot can you provide a description for this PR.

[Copilot]

@Pimentoso I've opened a new pull request, #114, to work on those changes. Once the pull request is ready, I'll request review from you.