557f6a1abc
Products now carry an optional categories relationship (backend: new product-categories collection mirroring the blog's categories pattern, migration applied and deployed). The shop page gains a left sidebar (styled like AccountNav) with a dual-handle price slider, category checkboxes, and an availability toggle — all instant-apply via searchParams, same union-filter semantics as the blog's category chips. Uncategorized products always match every category filter rather than disappearing. Also fixes CTA buttons sitting at different heights across sibling cards when one product's title wraps to two lines — MerklisteGrid.tsx and RelatedProducts.tsx get the same h-full/flex-1 spacer pattern ProductGrid.tsx already used.