Minor updates

[adamhathcock]

This pull request primarily updates the project to use a new solution file, SharpCompress.slnx, instead of the previous SharpCompress.sln. It also removes the .opencode/package-lock.json file and refines the Dependabot configuration for NuGet dependencies. Below are the most important changes:

Solution File Migration:

• Replaces all references to SharpCompress.sln with SharpCompress.slnx in documentation (AGENTS.md), VS Code settings (.vscode/settings.json), and all build-related VS Code tasks (.vscode/tasks.json). The old .sln file is deleted. [1] [2] [3] [4] [5] [6] [7]

Dependency and Automation Configuration:

• Removes the .opencode/package-lock.json file, cleaning up Node.js dependency tracking.
• Updates .github/dependabot.yml to:
  • Only manage NuGet dependencies (removes GitHub Actions updates).
  • Limit open pull requests to 2.
  • Group all dependencies together.
  • Ignore major version updates for all dependencies.

[Copilot]

Pull request overview

This PR migrates the repository’s primary solution entrypoint from SharpCompress.sln to the new XML-based SharpCompress.slnx, updates editor/task configuration accordingly, and tightens dependency automation by refining Dependabot settings and removing an unused Node lockfile.

Changes:

• Introduces SharpCompress.slnx and removes the legacy SharpCompress.sln.
• Updates VS Code settings/tasks and AGENTS.md to reference SharpCompress.slnx.
• Simplifies Dependabot to NuGet-only, groups updates, caps open PRs, and ignores semver-major updates; removes .opencode/package-lock.json.

Review notes (action requested):

• SharpCompress.sln.DotSettings is deleted as part of the migration. If the intention is to preserve ReSharper/Rider inspection/code-style settings, consider renaming/replacing it with an equivalent settings file associated with SharpCompress.slnx (otherwise teams relying on those settings will silently lose them).
• AGENTS.md still says “Use dotnet build to build the solution” while the repo no longer contains a conventional .sln. To avoid confusion (and potential breakage if the CLI doesn’t auto-discover .slnx), it would be clearer to document dotnet build SharpCompress.slnx / dotnet test SharpCompress.slnx.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
SharpCompress.slnx	Adds new solution definition listing projects and solution items.
SharpCompress.sln	Removes legacy Visual Studio .sln solution file.
SharpCompress.sln.DotSettings	Removes solution-bound JetBrains settings file.
AGENTS.md	Updates documented solution filename to .slnx.
.vscode/tasks.json	Updates build/restore/clean tasks to target .slnx.
.vscode/settings.json	Updates default solution setting to .slnx.
.opencode/package-lock.json	Removes Node lockfile under .opencode.
.github/dependabot.yml	Restricts Dependabot to NuGet, groups updates, limits PRs, ignores majors.

Files not reviewed (1)

• .opencode/package-lock.json: Language not supported

[Copilot]

Pull request overview

Copilot reviewed 13 out of 14 changed files in this pull request and generated no new comments.

Files not reviewed (1)

• .opencode/package-lock.json: Language not supported