feat(help): Add floating help button to all pages

Replaced inline HelpButton components with a global FloatingHelpButton
that appears fixed in the top-right corner of all pages. The button:
- Automatically detects the current route and links to the appropriate help page
- Uses a consistent position across all pages (fixed, top-right)
- Is hidden on help pages themselves
- Works on both business and platform layouts

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

frontend/src/pages/Customers.tsx

@@ -16,7 +16,6 @@ import {
   Eye
 } from 'lucide-react';
 import Portal from '../components/Portal';
-import HelpButton from '../components/HelpButton';
 
 interface CustomersProps {
   onMasquerade: (user: User) => void;
@@ -126,12 +125,9 @@ const Customers: React.FC<CustomersProps> = ({ onMasquerade, effectiveUser }) =>
   return (
     <div className="p-8 max-w-7xl mx-auto space-y-6">
       <div className="flex flex-col sm:flex-row sm:items-center justify-between gap-4">
-        <div className="flex items-start gap-4">
-          <div>
-            <h2 className="text-2xl font-bold text-gray-900 dark:text-white">{t('customers.title')}</h2>
-            <p className="text-gray-500 dark:text-gray-400">{t('customers.description')}</p>
-          </div>
-          <HelpButton helpPath="/help/customers" />
+        <div>
+          <h2 className="text-2xl font-bold text-gray-900 dark:text-white">{t('customers.title')}</h2>
+          <p className="text-gray-500 dark:text-gray-400">{t('customers.description')}</p>
         </div>
         <button
           onClick={() => setIsAddModalOpen(true)}