ui: remove footer hints and floating feedback entry points

src/components/Shell.tsx

@@ -3,7 +3,6 @@ import { motion } from 'motion/react';
 import { Building2, ChevronRight, ShieldCheck } from 'lucide-react';
 import { useAuth } from '../auth/useAuth';
 import { DemoModeProvider } from './Blur';
-import FeedbackFab from './FeedbackFab';
 import { cn } from '../lib/cn';
 import { LoadingState } from './ui/surface';
 
@@ -91,7 +90,7 @@ export function Shell({ modules }: { modules: ModuleConfig[] }) {
 
   return (
     <DemoModeProvider enabled={false}>
-    <div className="enterprise-grid-bg flex min-h-screen">
+    <div className="app-shell enterprise-grid-bg flex min-h-screen">
       {/* 全局水印 */}
       <div className="fixed inset-0 pointer-events-none z-[9999] overflow-hidden" style={{ opacity: 0.06 }}>
         <div className="absolute inset-0" style={{
@@ -156,7 +155,7 @@ export function Shell({ modules }: { modules: ModuleConfig[] }) {
       </nav>
 
       {/* 内容区 */}
-      <main className="min-w-0 flex-1 pb-16 md:ml-20 md:pb-0" style={{ overflowX: 'clip' }}>
+      <main className="app-shell-content min-w-0 flex-1 pb-16 md:ml-20 md:pb-0" style={{ overflowX: 'clip' }}>
         <div className="pointer-events-none fixed left-20 right-0 top-0 z-20 hidden h-12 items-center border-b border-white/60 bg-white/55 px-6 text-xs font-bold text-slate-400 backdrop-blur-xl md:flex">
           <span className="text-slate-600">羚牛氢能 BI</span>
           <span className="mx-2 text-slate-300">/</span>
@@ -165,11 +164,11 @@ export function Shell({ modules }: { modules: ModuleConfig[] }) {
         <Suspense fallback={<div className="p-3 md:p-6"><LoadingState label="正在加载业务模块" /></div>}>
           {ActiveComponent && <ActiveComponent />}
         </Suspense>
-        {activeModule !== 'assets' && <FeedbackFab module={activeModule} />}
+
       </main>
 
       {/* 移动端底部导航 (md 以下) */}
-      <nav className="fixed inset-x-0 bottom-0 z-50 border-t border-white/70 bg-white/92 px-3 pb-[max(0.5rem,env(safe-area-inset-bottom))] pt-2 shadow-[0_-18px_40px_rgba(15,23,42,0.08)] backdrop-blur-xl md:hidden">
+      <nav className="app-mobile-nav fixed inset-x-0 bottom-0 z-50 border-t border-white/70 bg-white/92 px-3 pb-[max(0.5rem,env(safe-area-inset-bottom))] pt-2 shadow-[0_-18px_40px_rgba(15,23,42,0.08)] backdrop-blur-xl md:hidden">
         <div className="grid gap-1" style={{ gridTemplateColumns: `repeat(${modules.length}, minmax(0, 1fr))` }}>
         {modules.map((m) => {
           const Icon = m.icon;