rename(cleanup): drop last capakraken strings from UI, scripts, schema, tests

AppShell.tsx top-left brand → Nexus (desktop sidebar + mobile top-bar),
shell echo strings, prisma schema header, test fixture token, playwright
runtime DB URL.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/layout/AppShell.tsx

@@ -450,7 +450,7 @@ function SidebarContent({
           {!sidebarCollapsed && (
             <div className="overflow-hidden">
               <h1 className="font-display text-xl font-semibold text-gray-900 dark:text-gray-50">
-                Capa<span className="text-brand-600">Kraken</span>
+                Nex<span className="text-brand-600">us</span>
               </h1>
               <p className="text-xs uppercase tracking-[0.18em] text-gray-500 dark:text-gray-400">
                 Resource & Capacity Planning
@@ -984,7 +984,7 @@ export function AppShell({
               <HamburgerIcon />
             </button>
             <span className="ml-3 font-display text-sm font-semibold text-gray-900 dark:text-gray-50">
-              Capa<span className="text-brand-600">Kraken</span>
+              Nex<span className="text-brand-600">us</span>
             </span>
           </div>
           <PageTransition>{children}</PageTransition>