Migrate Container Apps tools to new tool design

[alzimmermsft]

What does this PR do?

Migrates Container Apps tools to new design where Register and Bind options are based on Option attributes.

GitHub issue number?

[Link to the GitHub issue this PR addresses]

Pre-merge Checklist

• Required for All PRs
  • Read contribution guidelines
  • PR title clearly describes the change
  • Commit history is clean with descriptive messages (cleanup guide)
  • Added comprehensive tests for new/modified functionality
  • Created a changelog entry if the change falls among the following: new feature, bug fix, UI/UX update, breaking change, or updated dependencies. Follow the changelog entry guide
• For MCP tool changes:
  • One tool per PR: This PR adds or modifies only one MCP tool for faster review cycles
  • Updated servers/Azure.Mcp.Server/README.md and/or servers/Fabric.Mcp.Server/README.md documentation
  • Validate README.md changes running the script ./eng/scripts/Process-PackageReadMe.ps1. See Package README
  • For new or modified tool descriptions, ran ToolDescriptionEvaluator and obtained a score of 0.4 or more and a top 3 ranking for all related test prompts
  • For tools with new names, including new tools or renamed tools, update consolidated-tools.json
  • For renamed tools, follow the Tool Rename Checklist and tag the PR with the breaking-change label
  • For new tools associated with Azure services or publicly available tools/APIs/products, add URL to documentation in the PR description
• Extra steps for Azure MCP Server tool changes:
  • Updated command list in servers/Azure.Mcp.Server/docs/azmcp-commands.md
  • Ran ./eng/scripts/Update-AzCommandsMetadata.ps1 to update tool metadata in azmcp-commands.md (required for CI)
  • Updated test prompts in servers/Azure.Mcp.Server/docs/e2eTestPrompts.md
  • 👉 For Community (non-Microsoft team member) PRs:
    • Security review: Reviewed code for security vulnerabilities, malicious code, or suspicious activities before running tests (crypto mining, spam, data exfiltration, etc.)
    • Manual tests run: added comment /azp run mcp - pullrequest - live to run Live Test Pipeline

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[Copilot]

Pull request overview

This PR migrates the Azure Container Apps tool to the newer command/options design that binds CLI options via [Option] / [OptionContainer] attributes and uses the two-generic SubscriptionCommand<TOptions, TResult> pattern.

Changes:

• Refactors ContainerAppListCommand to use SubscriptionCommand<ContainerAppListOptions, TResult> and attribute-based option binding (removing the legacy RegisterOptions/BindOptions approach).
• Updates unit tests to use SubscriptionCommandUnitTestsBase and removes the Container Apps test assembly attributes file.
• Updates project references to use $(RepoRoot) in two tool .csproj files and adds a changelog entry.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tools/Azure.Mcp.Tools.Cosmos/src/Azure.Mcp.Tools.Cosmos.csproj	Switches Azure.Mcp.Core project reference to $(RepoRoot) (scope note: touches Cosmos in a Container Apps PR).
tools/Azure.Mcp.Tools.ContainerApps/tests/Azure.Mcp.Tools.ContainerApps.Tests/ContainerApp/ContainerAppListCommandTests.cs	Migrates tests to SubscriptionCommandUnitTestsBase and simplifies validation setup.
tools/Azure.Mcp.Tools.ContainerApps/tests/Azure.Mcp.Tools.ContainerApps.Tests/AssemblyAttributes.cs	Removes assembly-level test attributes (env var clearing + collection behavior).
tools/Azure.Mcp.Tools.ContainerApps/src/Options/ContainerApp/ContainerAppListOptions.cs	Replaces inherited options with a flat, attribute-bound options POCO implementing ISubscriptionOption.
tools/Azure.Mcp.Tools.ContainerApps/src/GlobalUsings.cs	Removes global System.CommandLine using.
tools/Azure.Mcp.Tools.ContainerApps/src/Commands/ContainerAppsJsonContext.cs	Converts JSON context type to file-scoped declaration.
tools/Azure.Mcp.Tools.ContainerApps/src/Commands/ContainerApp/ContainerAppListCommand.cs	Converts command to two-generic subscription command and updates execution signature to take bound options.
tools/Azure.Mcp.Tools.ContainerApps/src/Commands/BaseContainerAppsCommand.cs	Deletes legacy base command that performed manual option registration/binding.
tools/Azure.Mcp.Tools.ContainerApps/src/Azure.Mcp.Tools.ContainerApps.csproj	Switches Azure.Mcp.Core reference to $(RepoRoot) and removes direct System.CommandLine package reference.
servers/Azure.Mcp.Server/changelog-entries/1784324895091.yaml	Adds changelog entry describing breaking changes for Container Apps tool parameters.

Comments suppressed due to low confidence (1)

tools/Azure.Mcp.Tools.ContainerApps/tests/Azure.Mcp.Tools.ContainerApps.Tests/AssemblyAttributes.cs:1

• The test project no longer has the assembly-level attributes that clear known environment variables before each test run. Other tool test projects in this repo keep these attributes to prevent ambient CI/dev environment variables (e.g., AZURE_SUBSCRIPTION_ID, proxies, auth settings) from influencing unit tests and to keep xUnit isolation consistent.