nx_kit_shell.nx

nx_kit_shell.nx -- the ONE shared shell-neutralisation layer every design family composes (rule 15: the pattern appeared in 3 families, so it belongs in one place). ★WHY THIS EXISTS: a family restyles the SHARED page shell (nx_sclass_kit's header/footer chrome), and three separate hard-won facts about that shell were being re-derived and re-typed per family: 1. the base `.bar` is a FIXED-HEIGHT STICKY FLEX bar -- a family that makes its nav a block MUST also reset height/min-height/position/overflow or the nav renders OUTSIDE the header (the Journal masthead collided with the lead's kicker line until this was found by rendering, 07-25); 2. the shell's brand mark is a GRADIENT DOT -- any family with its own wordmark must suppress it in BOTH the header AND the footer (the footer copy survived the header fix and was caught by a second render pass); 3. doc-tier form controls (.field input/.btnp) carry SaaS defaults -- rounded fields and a gradient submit -- which every non-SaaS family has to re-square. Each helper takes only what genuinely varies (a token name, a radius), so this is composition, not a configuration flag farm (rule 22). Pure emit. license_tier: ORIGINAL