feat: support root configuration overrides and polish for v1.1.0 release

[GhostwheeI]

• Added support for root-level configuration file overrides (server-settings.json, server-adminlist.json) to streamline management.
• Parity implemented in both FactorioServerManager.ps1 and example_batch.bat.
• "Edit settings" menu option intelligently targets the active configuration.
• Version bumped across scripts and CHANGELOG.md to 1.1.0.
• Expanded documentation in README.md to cover root configuration overrides and polish the repository for an official release.
• Created verify_syntax.py helper script to ensure syntax integrity of shell scripts in the Linux test sandbox.

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PR created automatically by Jules for task 8217425038433909902 started by @GhostwheeI

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