Implements a new `/core:todo` command to extract and track TODO/FIXME comments from the codebase. The command is powered by a new shell script `claude/code/scripts/todo.sh`.
The script scans the repository for `TODO:`, `FIXME:`, `HACK:`, and `XXX:` comments. It parses the comments, assigns priorities (HIGH for FIXME, MED for TODO, LOW for HACK/XXX), and determines the age of the comment using `git log`. The command also supports a `--priority` flag to sort the output.
During development, the script suffered from a silent failure. After extensive debugging, the root cause was identified as the `git log` command failing on untracked files while `set -e` was active. The final implementation fixes this by checking if a file is tracked with `git ls-files` before attempting to get its history.
