Phases 5-7: Dashboard UI, Admin API, and Auth middleware

Phase 5 - Main Dashboard:
- Dashboard overview page with system health stats
- Jobs by status breakdown, success rates, top clients
- Dashboard API (/api/dashboard/overview, by-client, problems, by-version)

Phase 6 - Admin/Scraper Management:
- Scrapers management page with traffic allocation UI
- Admin API for scraper CRUD operations
- Traffic percentage updates for A/B testing
- Promote/deprecate scraper versions

Phase 7 - Authentication:
- API key authentication middleware
- SHA-256 key hashing (keys never stored in plain text)
- Scope-based authorization (jobs:read, jobs:write, admin)
- Rate limiting per API key

Also:
- Updated api_server_production.py to include new routers
- Extended core/database.py with dashboard query methods
- Added dashboard link to sidebar navigation
- Updated CONTEXT-KEEPER.md to mark all phases complete

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

web/components/Sidebar.tsx

@@ -9,6 +9,16 @@ export default function Sidebar() {
   const { jobs } = useJobs();
 
   const navItems = [
+    {
+      href: '/dashboard',
+      icon: (
+        <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-6 0a1 1 0 001-1v-4a1 1 0 011-1h2a1 1 0 011 1v4a1 1 0 001 1m-6 0h6" />
+        </svg>
+      ),
+      label: 'Home',
+      matchPaths: ['/dashboard'],
+    },
     {
       href: '/new',
       icon: (
@@ -40,6 +50,16 @@ export default function Sidebar() {
       label: 'Analytics',
       matchPaths: ['/analytics'],
     },
+    {
+      href: '/dashboard/scrapers',
+      icon: (
+        <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M10 20l4-16m4 4l4 4-4 4M6 16l-4-4 4-4" />
+        </svg>
+      ),
+      label: 'Scrapers',
+      matchPaths: ['/dashboard/scrapers'],
+    },
   ];
 
   const isActive = (item: typeof navItems[0]) => {