Replace the ad-hoc upload/browse/URL blocks in ImageStylePanel, HeroStylePanel
(bgImage + bgVideo), BackgroundSectionStylePanel, NavStylePanel (standalone
Logo imageSrc + Navbar logoImage), MediaStylePanel (Gallery/ContentSlider
array items), and FeaturesEditor (per-feature image) with the shared
AssetPicker component, dropping each panel's duplicated local
showBrowser/browserAssets/handleUpload state and inline asset-browser JSX.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>