Refactor CLI download scripts to extract shared code blocks

[radical]

This PR refactors the Aspire CLI download scripts (get-aspire-cli.ps1 and get-aspire-cli.sh) to improve code organization and prepare for code reuse in upcoming features.

Key Changes

Code Organization & Reusability

• Extracted common helper functions into clearly marked shared code blocks in both PowerShell and Bash scripts
• Added # START: Shared code and # END: Shared code markers to identify reusable components
• Consolidated utility functions like platform detection, temporary directory management, and archive handling

Enhanced Functionality

• PowerShell: Added proper comment-based help documentation with comprehensive examples and usage patterns
• Bash: Improved argument parsing and error handling with better user feedback
• Both: Extracted default install path logic into reusable helper functions for better code organization
• Both: Enhanced archive detection using file extensions instead of OS-dependent logic

Improved Helper Functions

• PowerShell: Added Get-RuntimeIdentifier, New-TempDirectory, Remove-TempDirectory, and Get-DefaultInstallPrefix
• Bash: Added get_runtime_identifier, new_temp_dir, remove_temp_dir, and improved platform detection functions
• Both: Better cross-platform compatibility and error handling

Code Quality Improvements

• Removed deprecated features (like custom -Help parameter in PowerShell) in favor of standard help mechanisms
• Improved logging and verbose output consistency across both scripts
• Better separation of concerns with dedicated functions for specific operations

Impact

This refactoring maintains full backward compatibility while making the codebase more maintainable and setting up the foundation for a future PR that will introduce get-aspire-cli-pr scripts to download CLI builds from specific pull requests, leveraging these shared building blocks.

[Copilot]

Pull Request Overview

This PR refactors the Aspire CLI download scripts to improve code organization by extracting shared functionality into clearly marked code blocks, preparing the foundation for code reuse in future features.

• Extracts common helper functions into shared code sections marked with START/END comments
• Enhances documentation with comprehensive PowerShell help and improved argument parsing in Bash
• Improves cross-platform compatibility with better archive detection and platform-specific handling

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
eng/scripts/get-aspire-cli.sh	Refactored to extract shared helper functions, improved argument parsing with renamed variables, and enhanced cross-platform archive handling
eng/scripts/get-aspire-cli.ps1	Added comprehensive comment-based help documentation, extracted shared functions, and improved code organization with better separation of concerns

[Copilot]

Using unquoted EOF delimiter makes the heredoc subject to variable expansion. This could cause issues if variables contain special characters. Use quoted 'EOF' to prevent expansion: cat << 'EOF'

[Copilot]

[nitpick] The wildcard pattern in the comment 'get-aspire-cli*.sh script' is unclear and doesn't match the actual filename pattern. Consider using a more descriptive comment like 'Added by Aspire CLI installation script'.

Suggested change

	echo -e "\n# Added by get-aspire-cli*.sh script" >> "$config_file"
	echo -e "\n# Added by Aspire CLI installation script" >> "$config_file"

[Copilot]

This condition will execute the block when DRY_RUN is false, but the following printf and say_info statements should be shown in both dry-run and normal execution modes since they are informational messages about what to do after installation.

Suggested change

	if [[ "$DRY_RUN" != true ]]; then
	printf "\nTo use the Aspire CLI in new terminal sessions, restart your terminal or run:\n"
	say_info " source $config_file"
	fi
	printf "\nTo use the Aspire CLI in new terminal sessions, restart your terminal or run:\n"
	say_info " source $config_file"