feat: remove Administration workspace — keep only Verwaltung + Suche

- Delete all ops page components (ReviewQueue, AIMonitoring, Governance,
  SourceMonitoring, ActivityTimeline, SignalPipeline)
- Remove OPERATIONS workspace from AppShell config, nav order, path detection
- Remove all /ops/* routes from App.tsx
- Remove WorkspaceType.OPERATIONS from allowedWorkspaces in authService,
  sessionStore, permissions
- Keep MarketIntelligence page (already moved to /supply/market-intelligence)

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

.claude/worktrees/agent-a82a3716/src/components/compare/CompareEmptyState.tsx

@@ -0,0 +1,24 @@
+import { Box, Button, Typography } from '@mui/material'
+import { Columns2 } from 'lucide-react'
+import { useNavigate } from 'react-router'
+
+export function CompareEmptyState() {
+  const navigate = useNavigate()
+  return (
+    <Box sx={{ px: 3, py: 4 }}>
+      <Box sx={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 2, py: 8 }}>
+        <Columns2 size={40} color="#94a3b8" />
+        <Typography variant="h6" color="text.secondary" sx={{ fontWeight: 600 }}>
+          Keine Ergebnisse zum Vergleich
+        </Typography>
+        <Typography variant="body2" color="text.secondary" sx={{ textAlign: 'center', maxWidth: 360 }}>
+          Fügen Sie 2–4 Ergebnisse aus dem Feed, Match Detail oder Match Center zum Vergleich hinzu.
+        </Typography>
+        <Button variant="contained" size="small" onClick={() => navigate('/demand/results')}
+          sx={{ bgcolor: '#1e3a5f', '&:hover': { bgcolor: '#162d4a' } }}>
+          Zu den Suchergebnissen
+        </Button>
+      </Box>
+    </Box>
+  )
+}