docs: Add interface and class documentation

[thomhurst]

Summary

• Add class-level XML documentation for ICommand interface describing it as the core abstraction for executing command line tools and processes
• Add class-level XML documentation for AzureExtensions class with summary and remarks about using context.Azure()
• Add method-level documentation for the public RegisterAzureContext extension method

Test plan

• Build ModularPipelines.csproj - verified success
• Build ModularPipelines.Azure.csproj - verified success

Closes #1650
Closes #1621

🤖 Generated with Claude Code

[thomhurst]

Summary

Adds XML documentation comments to Azure extension methods and ICommand interface.

Critical Issues

None found ✅

Analysis

I've verified the documentation accuracy:

1. AzureExtensions.cs (lines 21-31):

   • Class-level documentation correctly describes the extension methods
   • The context.Azure() usage example is accurate (verified in src/ModularPipelines.Examples/Modules/Azure/)
   • The extension method exists as Azure(this IPipelineHookContext) which works for IPipelineContext since it inherits from IPipelineHookContext
   • RegisterAzureContext method documentation accurately describes its purpose

2. ICommand.cs (lines 6-9):

   • Interface-level documentation provides helpful context
   • Cross-references to IBash and IPowershell are valid (both interfaces exist)
   • Clarifies the relationship between the generic command interface and shell-specific ones

The documentation follows standard XML doc conventions and adds value for API consumers without changing any functionality.

Verdict

✅ APPROVE - No critical issues