Update egg-windrose.json

[nimauria]

Description

This PR fixes several Windrose-specific compatibility issues in the egg configuration.

Changes:

• update the startup done trigger to use UEngine::LoadMap Load map complete
• change Windrose boolean-style config values from 0/1 handling to explicit true/false
• validate MAX_PLAYERS as an integer instead of a generic string
• lower the default player count from 8 to 4 to better reflect recommended performance for smaller servers

Why:
Windrose reads values from R5/ServerDescription.json, and several fields are more reliable when passed in the format the game expects rather than generic panel-style boolean handling. This PR keeps the egg structure intact while correcting value formats and validation for the game’s config.

The current egg uses panel boolean-style 0/1 defaults and validation for settings that are written directly into ServerDescription.json. For Windrose, explicit true/false values are more reliable for these config fields and avoid values being ignored or mishandled by the game.

Checklist for all submissions

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you tested and reviewed your changes with confidence that everything works?
• Did you branch your changes and PR from that branch and not from your master branch?
  • If not, why?:

• You verify that the start command applied does not use a shell script
  • If some script is needed then it is part of a current yolk or a PR to add one
• The egg was exported from the panel