Add LM Studio translator endpoint

[hvboq]

Summary

Adds an LM Studio translator endpoint for local OpenAI-compatible chat completion servers.

This lets users run translations through LM Studio's local server, which can be faster for local workflows and avoids routing requests through external hosted APIs.

Changes

• Add LmStudioTranslate endpoint using LM Studio's default OpenAI-compatible /v1/chat/completions API.
• Add LmStudio.yaml sample configuration.
• Document LM Studio setup and endpoint selection in the README.
• Add config tests for the LM Studio sample.
• Fix glossary prompt override loading so *-GlossaryPrompt.txt updates GlossaryPrompt.
• Update ILRepack packaging so release builds merge only YamlDotNet and work with current .NET SDK tooling.

Validation

• dotnet build XUnity.AutoTranslate.LlmTranslators.sln -c Debug --no-restore
• dotnet build XUnity.AutoTranslate.LlmTranslators.sln -c Release --no-restore
• $env:DOTNET_ROLL_FORWARD='Major'; dotnet test XUnity.AutoTranslate.LlmTranslators.sln -c Release --no-build --filter "FullyQualifiedName!~PromptTests"

Note: PromptTests were excluded because they call live OpenAI/Ollama/LLM endpoints.