Disable Reveal.js default controls, add custom bottom nav

Add critical Reveal.js config rule to prevent blank slides

Fix Chart.js CDN URL: chart.min.js → chart.umd.min.js

Default output path to ~/Downloads/ instead of working directory

Merge branch 'main' of https://github.com/careerhackeralex/visualize

eval: round 58 complete — avg 8.44, gate ACCEPTABLE

Bump marketplace.json to v0.4.0 (was missed in prior version bump)

Bump to v0.4.0

Auto-open + return clickable URL after creating visualization

Fix README installation instructions for Claude Code plugin

eval: round 57 complete — avg 7.85, gate NEEDS WORK

eval: round 57 fixes — mandatory utility menu, correct CSS properties, theme classes, chart animation disable

eval: round 56 complete — avg 8.53, gate ACCEPTABLE

eval: round 56 fixes — Chart.js config clarity, slide spacing, ChartManager enhancement

eval: round 55 complete — avg 7.93, gate NEEDS WORK