fix(windows): use spawn instead of exec for Symfony console commands

[Perchusha]

Problem

On Windows, Storybook’s Symfony integration was using child_process.exec() to run commands formatted as one big, single‑quoted string (e.g. ’php’ ’bin/console’ …). In cmd.exe, single quotes aren’t treated as delimiters, so the command fails with:

’’php’’ is not recognized as an internal or external command…

See issue #43 for details.

Solution

This PR replaces the fragile exec(string) approach with child_process.spawn() and an explicit argument array.

• Cross‑platform: passing command and args[] directly avoids any quoting/parsing quirks on Windows, macOS or Linux.
• Readability: the code now clearly separates the executable (php) from its arguments (bin/console, debug:container, etc.).
• Error handling: exit codes and stdout/stderr are captured and surfaced exactly as before.

What’s Changed

• Removed: import { exec } from 'child_process' and the old execSymfonyCommand(finalCommand: string) function body.
• Added: import { spawn } from 'child_process' and a new execSymfonyCommand(command: string, args: string[]): Promise that uses spawn(..., { shell: true }).
• Updated: runSymfonyCommandJson (and any direct callers) to call execSymfonyCommand('php', ['bin/console', command, …]) instead of building a single interpolated string.
• Tests: manually verified on Windows 10 and Linux; npm run build and npm run storybook now succeed without quoting errors.