.NET code patching template + infrastructure

[m-redding]

Resolves: #14274

Adds the .NET equivalent of the Java/Python error-driven patch template, enabling the customization repair pipeline to fix C# build errors in
partial-class customization files.

What's included

• DotnetErrorDrivenPatchTemplate — Prompt template grounded in Azure SDK for .NET partial-class patterns (Generated/ folder, .cs
  customizations)
• DotnetLanguageService.ApplyPatchesAsync — Wires up the patch agent with ReadFile, GrepSearch, CodePatch, and a new RenameFile tool
• FileTools.CreateRenameFileTool — New tool for renaming customization files when a class is renamed (with path-traversal protection)
• Logging fix — Suppress Copilot SDK noise even in debug mode

.NET-specific additions over Java/Python

• Filters out Generated/ folder files from customization file discovery
• Early-exits when no .cs files exist (avoids unnecessary agent invocation)
• RenameFile tool for class-rename scenarios (file name must match class name in .NET)
• Prompt guidance for cascading errors and analyzer rule suppression

Tests

• DotnetErrorDrivenPatchTemplateTests — Prompt content validation
• DotnetLanguageServicePatchTests — Agent invocation, error handling, Generated file exclusion, cancellation propagation
• FileToolsTests (RenameFile) — Success, security (path traversal), edge cases

[Copilot]

Pull request overview

Adds .NET support to azsdk-cli’s error-driven customization repair pipeline, aligning with the existing Java/Python patch-agent flow while accounting for .NET partial-class conventions (e.g., Generated/ vs customization files and class/file rename coupling).

Changes:

• Introduces DotnetErrorDrivenPatchTemplate to guide an agent to apply safe, surgical fixes to C# customization files based on build errors.
• Wires DotnetLanguageService.ApplyPatchesAsync to run the patch agent with ReadFile, GrepSearch, CodePatchTool, and a new RenameFile tool (with generated-code exclusion and early exit when no .cs files exist).
• Adds FileTools.CreateRenameFileTool (path-traversal protected) plus tests; also adjusts logging to always suppress Copilot SDK noise even in debug mode.

Reviewed changes

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

Show a summary per file

File	Description
tools/azsdk-cli/Azure.Sdk.Tools.Cli/Services/Languages/DotnetLanguageService.cs	Adds patch-agent execution for .NET customization repair, excludes Generated/, includes RenameFile tool.
tools/azsdk-cli/Azure.Sdk.Tools.Cli/Prompts/Templates/DotnetErrorDrivenPatchTemplate.cs	New .NET-specific error-driven patch prompt grounded in partial-class patterns and safe patching rules.
tools/azsdk-cli/Azure.Sdk.Tools.Cli/Program.cs	Always suppresses GitHub.Copilot.SDK logs below warning level, even in debug mode.
tools/azsdk-cli/Azure.Sdk.Tools.Cli/CopilotAgents/Tools/FileTools.cs	Adds RenameFile AIFunction with safe path resolution and basic rename validations.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Tools/Package/SdkBuildToolTests.cs	Updates DotnetLanguageService construction for new ICopilotAgentRunner dependency.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Tools/Package/PackToolTests.cs	Updates DotnetLanguageService construction for new ICopilotAgentRunner dependency.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Tools/Generators/SampleGeneratorToolTests.cs	Updates DotnetLanguageService construction for new ICopilotAgentRunner dependency.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Services/Languages/LanguageServicePackageInfoTests.cs	Updates DotnetLanguageService construction for new ICopilotAgentRunner dependency.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Services/Languages/DotnetLanguageServicePatchTests.cs	New tests validating .NET patch agent invocation behavior, exclusions, and cancellation propagation.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Services/Languages/DotNetLanguageSpecificChecksTests.cs	Updates DotnetLanguageService construction for new ICopilotAgentRunner dependency.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Prompts/Templates/DotnetErrorDrivenPatchTemplateTests.cs	New tests validating prompt content and expected guidance/tool references.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/Helpers/DotNetPackageInfoHelperTests.cs	Updates DotnetLanguageService construction for new ICopilotAgentRunner dependency.
tools/azsdk-cli/Azure.Sdk.Tools.Cli.Tests/CopilotAgents/Tools/FileToolsTests.cs	Adds RenameFile tool tests (success, traversal protection, edge cases, callback, directory creation).