Fix confusing environment option help text in dotnet run command

[Copilot]

• Create plan for fixing confusing environment option help text
• Analyze the issue and understand that both dotnet run and dotnet test commands use same shared CommonOptions.EnvOption with test-specific text
• Design solution using factory method pattern similar to existing FrameworkOption
• Create CreateEnvOption(string description) factory method in CommonOptions
• Add separate CmdTestEnvironmentVariableDescription resource string for test-specific text
• Update CmdEnvironmentVariableDescription to contain generic text without test references
• Modify TestCommandParser to use test-specific description
• Fix option identity issue by creating separate TestEnvOption static field
• Update completion test snapshots for pwsh and zsh shells
• Verify all tests pass including environment variable functionality

Fixed issues:

• ✅ dotnet run --help now shows generic environment variable help without test-specific text
• ✅ dotnet test --help still shows "This will force the tests to be run in an isolated process."
• ✅ Environment variable passing functionality works correctly
• ✅ Completion tests pass with updated snapshots

The changes are minimal and surgical, maintaining backward compatibility while fixing the confusing help text issue reported in #50794.

@baronfel's note: I've reviewed this and am happy with the code.

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[baronfel]

This change is simple and appears correct in terms of making the test and other-command strings for the --env description different.

[Copilot]

Pull Request Overview

This PR fixes the confusing help string for the -e|--environment option in dotnet run --help that incorrectly showed test-specific text about forcing tests to run in an isolated process.

Key changes:

• Split the shared environment option description into generic and test-specific versions
• Modified the factory pattern to accept custom descriptions for environment options
• Updated test command to use test-specific description while other commands use generic description

Reviewed Changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 13 comments.

File	Description
src/Cli/dotnet/CommonOptions.cs	Created factory method CreateEnvOption to accept custom descriptions for environment options
src/Cli/dotnet/Commands/Test/TestCommandParser.cs	Updated to use test-specific environment description via new factory method
src/Cli/dotnet/CliStrings.resx	Added new CmdTestEnvironmentVariableDescription resource and removed test-specific text from generic description
src/Cli/dotnet/xlf/*.xlf	Updated localization files to reflect the resource string changes

[baronfel]

@copilot the pwsh and zsh test cases of VerifyCompletions are broken still, they probably need to be updated with the new description. In addition, the Microsoft.DotNet.Cli.Test.Tests.GivenDotnetTestContainsEnvironmentVariables.ItPassesEnvironmentVariablesFromCommandLineParametersWhenRunningViaCsproj test is failing.

[Copilot]

@copilot the pwsh and zsh test cases of VerifyCompletions are broken still, they probably need to be updated with the new description. In addition, the Microsoft.DotNet.Cli.Test.Tests.GivenDotnetTestC...

Fixed both issues you mentioned:

1. Completion test snapshots: Updated pwsh and zsh completion snapshots to reflect the new environment descriptions. The run command now shows generic text without test-specific references.

2. Environment variable test failure: Fixed the option identity issue that was causing GivenDotnetTestContainsEnvironmentVariables.ItPassesEnvironmentVariablesFromCommandLineParametersWhenRunningViaCsproj to fail. Created a separate TestEnvOption static field to ensure the test command parser and test command use the same option instance.

All tests now pass including the environment variable functionality. Commit: 4ff185d

[baronfel]

/backport to release/10.0.1xx

[github-actions]

Started backporting to release/10.0.1xx: https://github.com/dotnet/sdk/actions/runs/17812861821