Introduce QC-GATE station monitoring with stacked bar chart and filterable LOT table,
using Vue 3 SFC + ECharts via npm. Establishes the pure Vite page architecture pattern
(no Jinja2) for future page migration. Also removes stale design files and README.mdj.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
