Fix shellcheck warnings across all shell scripts

[lroolle]

Problem

Multiple shellcheck warnings found across shell scripts that should be addressed for better code quality:

claude.sh

• SC2155: Declare and assign separately to avoid masking return values (5 instances)
• SC2005: Useless echo with command substitution (4 instances)

claude-yolo

• SC2155: Declare and assign separately to avoid masking return values (2 instances)
• SC2206: Quote to prevent word splitting/globbing (1 instance)
• SC2086: Double quote to prevent globbing and word splitting (2 instances)

claudeb.sh

• SC2155: Declare and assign separately to avoid masking return values (1 instance)
• SC2181: Check exit code directly instead of using $? (2 instances)

docker-entrypoint.sh

• SC2012: Use find instead of ls for better filename handling (1 instance)
• SC2155: Declare and assign separately to avoid masking return values (2 instances)
• SC2178/SC2128: Array/string variable usage issues (6 instances)

Current Status

• CI currently set to severity: error to avoid blocking builds
• All scripts pass error-level checks
• Warnings should be addressed for better code quality

Implementation Plan

• Fix SC2155 warnings by separating declare and assign
• Fix SC2005 warnings by removing unnecessary echo
• Fix SC2086 warnings by adding proper quoting
• Fix SC2181 warnings by direct exit code checking
• Fix SC2178/SC2128 array handling issues
• Update CI to severity: warning after fixes

Priority

Low - warnings don't break functionality but improve code quality

Labels

• enhancement
• code-quality
• good first issue

[lroolle]

close by #16