feat(#10): SubModule.xml support

[ModerRAS]

Summary

• Create SubModule models (DO, DTO, Mapper)
• Implement SubModuleLoader with async support
• Support reading and writing SubModule.xml files
• Add comprehensive unit tests
• Support creating default SubModule.xml

Changes

• BannerlordModEditor.Common/Models/SubModule/SubModuleDO.cs - Domain objects
• BannerlordModEditor.Common/Models/SubModule/SubModuleDTO.cs - Data transfer objects
• BannerlordModEditor.Common/Models/SubModule/SubModuleMapper.cs - DO/DTO mapper
• BannerlordModEditor.Common/Models/SubModule/SubModuleLoader.cs - XML loader
• BannerlordModEditor.Common.Tests/Models/SubModule/SubModuleLoaderTests.cs - Unit tests

Closes #10

[Copilot]

Pull request overview

Adds end-to-end support for Bannerlord SubModule.xml by introducing domain/DTO models, mapping, an XML loader with async APIs, and unit tests validating load/save/default behaviors.

Changes:

• Added SubModule DO/DTO model graphs and a DO↔DTO mapper.
• Implemented SubModuleLoader to load/save SubModule.xml and create a default template.
• Added unit tests covering load/save (sync+async) and default creation.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
BannerlordModEditor.Common/Models/SubModule/SubModuleMapper.cs	Maps between DO and DTO representations used by serialization.
BannerlordModEditor.Common/Models/SubModule/SubModuleLoader.cs	Implements XML load/save + async wrappers + default template creation.
BannerlordModEditor.Common/Models/SubModule/SubModuleDTO.cs	Defines XML-serializable DTO object model for SubModule.xml.
BannerlordModEditor.Common/Models/SubModule/SubModuleDO.cs	Defines domain object model mirroring the DTO structure.
BannerlordModEditor.Common.Tests/Models/SubModule/SubModuleLoaderTests.cs	Validates loader behavior with temp files and basic XML samples.

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[Copilot]

Task.Run around synchronous file IO/serialization can cause unnecessary thread-pool usage and contention under load. Prefer implementing true async IO (e.g., async file read/write with useAsync: true, deserialize/serialize from/to an in-memory buffer) or remove the async methods and let callers decide whether to offload to the thread pool.

[Copilot]

Task.Run around synchronous file IO/serialization can cause unnecessary thread-pool usage and contention under load. Prefer implementing true async IO (e.g., async file read/write with useAsync: true, deserialize/serialize from/to an in-memory buffer) or remove the async methods and let callers decide whether to offload to the thread pool.

[Copilot]

This overload defaults to FileShare.None, which can unnecessarily lock SubModule.xml while reading and break scenarios where another process/thread needs to read the file concurrently. Consider using a FileStream overload that specifies an explicit FileShare (commonly FileShare.Read or FileShare.ReadWrite) for the read path.

Suggested change

	using var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read);
	using var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);

[Copilot]

The DO types are decorated with XML serialization attributes even though serialization is performed via SubModuleDTO + XmlSerializer(typeof(SubModuleDTO)). This duplicates the schema across DO/DTO and increases the risk of them drifting out of sync. Consider either (a) removing XML attributes from the DO classes (keep DTO as the serialization contract), or (b) consolidating to a single XML model to eliminate the mapper if separation isn’t needed.

Suggested change

	[XmlRoot("Module")]
	public class SubModuleDO
	{
	[XmlElement("Name")]
	public string Name { get; set; } = string.Empty;
	[XmlElement("Id")]
	public string Id { get; set; } = string.Empty;
	[XmlElement("Version")]
	public string Version { get; set; } = string.Empty;
	[XmlElement("SingleplayerModule")]
	public bool SingleplayerModule { get; set; } = true;
	[XmlElement("MultiplayerModule")]
	public bool MultiplayerModule { get; set; }
	[XmlArray("DependedModules")]
	[XmlArrayItem("Module")]
	public List<DependedModuleDO> DependedModules { get; set; } = new();
	[XmlArray("SubModules")]
	[XmlArrayItem("SubModule")]
	public List<SubModuleItemDO> SubModules { get; set; } = new();
	[XmlArray("Xmls")]
	[XmlArrayItem("XmlNode")]
	public List<XmlNodeDO> Xmls { get; set; } = new();
	[XmlArray("OptionalDependedModules")]
	[XmlArrayItem("Module")]
	public List<OptionalDependedModuleDO> OptionalDependedModules { get; set; } = new();
	}
	public class DependedModuleDO
	{
	[XmlAttribute("Id")]
	public string Id { get; set; } = string.Empty;
	}
	public class OptionalDependedModuleDO
	{
	[XmlAttribute("Id")]
	public string Id { get; set; } = string.Empty;
	}
	public class SubModuleItemDO
	{
	[XmlElement("Name")]
	public string Name { get; set; } = string.Empty;
	[XmlElement("DLLName")]
	public string DLLName { get; set; } = string.Empty;
	[XmlElement("SubModuleClassType")]
	public string SubModuleClassType { get; set; } = string.Empty;
	[XmlElement("IsOptional")]
	public bool IsOptional { get; set; }
	[XmlElement("IsTicked")]
	public bool IsTicked { get; set; } = true;
	[XmlArray("Tags")]
	[XmlArrayItem("Tag")]
	public List<SubModuleTagDO> Tags { get; set; } = new();
	}
	public class SubModuleTagDO
	{
	[XmlAttribute("Key")]
	public string Key { get; set; } = string.Empty;
	[XmlAttribute("Value")]
	public string Value { get; set; } = string.Empty;
	}
	public class XmlNodeDO
	{
	[XmlAttribute("Id")]
	public string Id { get; set; } = string.Empty;
	[XmlAttribute("Type")]
	public string Type { get; set; } = string.Empty;
	[XmlText]
	public class SubModuleDO
	{
	public string Name { get; set; } = string.Empty;
	public string Id { get; set; } = string.Empty;
	public string Version { get; set; } = string.Empty;
	public bool SingleplayerModule { get; set; } = true;
	public bool MultiplayerModule { get; set; }
	public List<DependedModuleDO> DependedModules { get; set; } = new();
	public List<SubModuleItemDO> SubModules { get; set; } = new();
	public List<XmlNodeDO> Xmls { get; set; } = new();
	public List<OptionalDependedModuleDO> OptionalDependedModules { get; set; } = new();
	}
	public class DependedModuleDO
	{
	public string Id { get; set; } = string.Empty;
	}
	public class OptionalDependedModuleDO
	{
	public string Id { get; set; } = string.Empty;
	}
	public class SubModuleItemDO
	{
	public string Name { get; set; } = string.Empty;
	public string DLLName { get; set; } = string.Empty;
	public string SubModuleClassType { get; set; } = string.Empty;
	public bool IsOptional { get; set; }
	public bool IsTicked { get; set; } = true;
	public List<SubModuleTagDO> Tags { get; set; } = new();
	}
	public class SubModuleTagDO
	{
	public string Key { get; set; } = string.Empty;
	public string Value { get; set; } = string.Empty;
	}
	public class XmlNodeDO
	{
	public string Id { get; set; } = string.Empty;
	public string Type { get; set; } = string.Empty;

[Copilot]

Using a hard-coded absolute path like /nonexistent/path/... can be brittle across OSes/environments (and in rare cases could exist or be accessible). Prefer generating a guaranteed-nonexistent path under the temp directory (e.g., Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString(), "SubModule.xml")) so the test remains deterministic.

Suggested change

	var result = _loader.Load("/nonexistent/path/SubModule.xml");
	Assert.Null(result);
	}
	[Fact]
	public async Task LoadAsync_ReturnsNullForNonExistentFile()
	{
	var result = await _loader.LoadAsync("/nonexistent/path/SubModule.xml");
	var nonExistentPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString(), "SubModule.xml");
	var result = _loader.Load(nonExistentPath);
	Assert.Null(result);
	}
	[Fact]
	public async Task LoadAsync_ReturnsNullForNonExistentFile()
	{
	var nonExistentPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString(), "SubModule.xml");
	var result = await _loader.LoadAsync(nonExistentPath);

[Copilot]

Using a hard-coded absolute path like /nonexistent/path/... can be brittle across OSes/environments (and in rare cases could exist or be accessible). Prefer generating a guaranteed-nonexistent path under the temp directory (e.g., Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString(), "SubModule.xml")) so the test remains deterministic.

Suggested change

	var result = _loader.Load("/nonexistent/path/SubModule.xml");
	Assert.Null(result);
	}
	[Fact]
	public async Task LoadAsync_ReturnsNullForNonExistentFile()
	{
	var result = await _loader.LoadAsync("/nonexistent/path/SubModule.xml");
	var nonExistentPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString(), "SubModule.xml");
	var result = _loader.Load(nonExistentPath);
	Assert.Null(result);
	}
	[Fact]
	public async Task LoadAsync_ReturnsNullForNonExistentFile()
	{
	var nonExistentPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString(), "SubModule.xml");
	var result = await _loader.LoadAsync(nonExistentPath);