ChainBranding gains a productName field (default "Explorer"). New helper
applyBrandEnvOverrides(b) layers NEXT_PUBLIC_BRAND_* env vars over the
bundled defaults so a deploy can rebrand any field — name, org, URLs,
logo SVG, favicon, product label — without rebuilding the bundle.
Operators set:
NEXT_PUBLIC_BRAND_NAME " Network"
NEXT_PUBLIC_BRAND_PRODUCT_NAME "Explorer"
NEXT_PUBLIC_BRAND_ORG_NAME " Labs"
NEXT_PUBLIC_BRAND_LOGO_CONTENT <inline svg>
...
to override; empty values fall through.
TopBar now reads chain.branding.productName instead of the hardcoded
"Lux Explorer" string. getCurrentChain() applies env overrides on every
read so a brand can be flipped at runtime via env / k8s ConfigMap.
The bundled LUX, ZOO, HANZO, SPC, PARS defaults stay as-is for OSS
shipping; the white-label "other" path keeps reading from
NEXT_PUBLIC_NETWORK_* (legacy keys) as well.