Sticky category sidebar with polish on Menu page (Minimal Light)

Category sidebar now stays fixed via position: sticky (top: 88px, tucked below the Minimal Light header) while the product grid scrolls independently. Adds dish counts per category (including a sitewide total on All Dishes, reordered to the bottom via CSS order — no DOM/JS changes), and a refined active-state indicator. CSS + one hidden-by-default markup addition — Khana Khazana's Menu page renders identically to before.