Hook-command relative-script risk detection greatly expanded

Claude Code can warn when a hook (a shell command that runs automatically at certain points, configured via plugins or settings) implicitly depends on the folder it's launched from, which can make it fail when run elsewhere. This detection was substantially expanded:

• it now strips hidden NUL bytes before decoding the script
• it recognizes more shells: ash, ksh, mksh, rbash, and fish
• it separates the shebang line (the #!/bin/... line that names the shell) from the rest of the script for more accurate analysis
• it adds a check specific to the csh shell for set path = (...) lines that contain relative or . (current directory) entries
• it detects relative file includes pulled in via make include or awk @include