fix: Replace deprecated String.prototype.substr()

[CommanderRoot]

String.prototype.substr() is deprecated so we replace it with String.prototype.slice() which works similarily but isn't deprecated.
.substr() probably isn't going away anytime soon but the change is trivial so it doesn't hurt to do it.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[mmattel]

@phil-davis Technically this looks feasable...

[dj4oC]

• Security: no findings — mechanical .substr() → .slice() replacement, no behavior change intended
• Stability: GitHub reports this PR as mergeable_state: blocked (likely merge conflicts or a required check gate) and it's had no activity since Aug 2022; 0 check runs on file for the head commit, so CI has never actually validated this against current master.
• Performance: no findings
• Test coverage: no tests added, but this is a pure API-rename refactor across 13 files with no logic change — low risk either way
• TODOs found: 0
• Dependency touched: no
• CI status: none reported (stale, blocked)

Verdict

Idea is fine and low-risk, but the PR is 4+ years stale and blocked/unmergeable in its current state. Needs a rebase against current master and a fresh CI run before it can be merged — not actionable as-is.

🤖 Automated review by Claude Code (security · stability · performance · coverage)

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[CommanderRoot]

Rebased against current master as requested by our overlords

[phil-davis]

I adjusted the commit and PR title to meet the new semantic commit rules.