fix: check if sudo command is available before using it in install.sh

[Copilot]

install.sh fails on systems without sudo installed (minimal containers, embedded systems) with sudo: command not found.

Changes

• Add command -v sudo check before setting SUDO_CMD
• If sudo unavailable, proceed without it (allows install when user already has write permissions)

# Before: unconditionally set sudo
SUDO_CMD="sudo"

# After: check availability first
if command -v sudo &> /dev/null; then
  SUDO_CMD="sudo"
else
  SUDO_CMD=""
fi

Original prompt

main: line 83: sudo: command not found
Failed to create /usr/local/bin directory. Please check your permissions and try again.

有些系统没有这个的，所以可以不需要，在最前面的地方检测一下

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 21.93%. Comparing base (1ca4237) to head (69bb28f).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #575   +/-   ##
=======================================
  Coverage   21.93%   21.93%           
=======================================
  Files          72       72           
  Lines        4815     4815           
=======================================
  Hits         1056     1056           
  Misses       3662     3662           
  Partials       97       97           

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[Copilot]

Pull request overview

This PR fixes an installation failure on systems without sudo installed (e.g., minimal containers, embedded systems) by adding a check for sudo availability before attempting to use it.

Key Changes:

• Add conditional check using command -v sudo to detect if sudo is available
• Set SUDO_CMD to empty string when sudo is not found, allowing installation to proceed if user already has write permissions

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[Copilot]

When sudo is not available, the script silently sets SUDO_CMD to empty string without informing the user. This could lead to confusing permission errors later (lines 88-92, 95-103) if the user doesn't have write permissions to /usr/local/bin. Consider adding a warning message here to inform users that sudo is not available and they will need appropriate permissions to install to /usr/local/bin.

Suggested change

	else
	else
	echo "Warning: 'sudo' command not found. Proceeding without sudo."
	echo "Installation directory is '${INSTALL_DIR}'. Ensure you have write permissions to this directory (for example, run this script as root)."