feat: integrate contextual links and fix coupons navigation

- Added DocLink component and mapped routes
- Fixed Coupons nav link to /marketing/coupons
- Updated Settings pages to show inline documentation links

admin-spa/src/components/DocLink.tsx

@@ -0,0 +1,26 @@
+import React from 'react';
+import { useLocation } from 'react-router-dom';
+import { BookOpen } from 'lucide-react';
+import { getDocUrl } from '@/config/docRoutes';
+import { Button } from '@/components/ui/button';
+
+export function DocLink() {
+    const location = useLocation();
+    const docUrl = getDocUrl(location.pathname);
+
+    if (!docUrl) return null;
+
+    return (
+        <Button
+            variant="ghost"
+            size="icon"
+            className="h-8 w-8 ml-2 text-muted-foreground hover:text-primary"
+            asChild
+        >
+            <a href={docUrl} target="_blank" rel="noopener noreferrer" title="View Documentation">
+                <BookOpen className="h-4 w-4" />
+                <span className="sr-only">View Documentation</span>
+            </a>
+        </Button>
+    );
+}

admin-spa/src/components/PageHeader.tsx

@@ -7,6 +7,8 @@ interface PageHeaderProps {
   hideOnDesktop?: boolean;
 }
 
+import { DocLink } from '@/components/DocLink';
+
 export function PageHeader({ fullscreen = false, hideOnDesktop = false }: PageHeaderProps) {
   const { title, action } = usePageHeader();
   const location = useLocation();
@@ -24,8 +26,9 @@ export function PageHeader({ fullscreen = false, hideOnDesktop = false }: PageHe
   return (
     <div className={`sticky top-0 z-20 border-b bg-background ${hideOnDesktop ? 'md:hidden' : ''}`}>
       <div className={`${containerClass} px-4 py-3 flex items-center justify-between min-w-0`}>
-        <div className="min-w-0 flex-1">
+        <div className="min-w-0 flex-1 flex items-center">
           <h1 className="text-lg font-semibold truncate">{title}</h1>
+          <DocLink />
         </div>
         {action && <div className="flex-shrink-0 ml-4">{action}</div>}
       </div>