Document call-site behavior for list_remove and git pull retries

[codeforester]

Summary

Claude's follow-up review found two remaining documentation gaps at function call sites:

• list_remove removes all matching elements in one call, but lib/bash/list/lib_list.sh has no function comment stating that all occurrences are removed.
• git_update_repo honors BASE_GIT_PULL_MAX_ATTEMPTS through _git_pull_with_retry, but the git_update_repo function comment does not mention the environment variable.

The README-level docs already cover these behaviors; the fix is to make the function comments match the public behavior visible near the implementation.

Acceptance criteria

• Add a list_remove function comment that explicitly says every exact match is removed.
• Add a git_update_repo comment line documenting BASE_GIT_PULL_MAX_ATTEMPTS and its default behavior.
• Keep this as documentation-only/source-comment work unless validation reveals a real behavior issue.

Validation

• Run focused validation for affected docs/source comments.
• Run the repository validation gate if the touched comments are covered by lint or docs checks.