feat: F008 AI need builder — smart parse, criteria review, follow-up & weighting

Domain: ParsedNeedCriteria, FollowUpQuestion, ParseNeedResult, NeedBuilderStep, WEIGHTING_KEYS/LABELS. Services: weightingService (asset-type profiles), aiService extended with parseNeed (keyword extraction mock, 1.4s delay) and generateFollowUpQuestions. Components: NeedBuilderProgress, NeedInput, ConfidenceFieldBadge, ExtractedFieldRow, CriteriaReviewPanel, FollowUpQuestionCard, FollowUpPanel, WeightingEditor, NeedCardPreview, NeedBuilderErrorState. Page: AINeedBuilderPage replaces AISearch with 4-step flow (input → review → weighting → save).

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

src/components/demand/NeedBuilderErrorState.tsx

@@ -0,0 +1,31 @@
+import { Box, Button, Typography } from '@mui/material'
+import { AlertTriangle, RotateCcw } from 'lucide-react'
+
+interface Props {
+  message: string
+  onRetry: () => void
+}
+
+export function NeedBuilderErrorState({ message, onRetry }: Props) {
+  return (
+    <Box sx={{ display: 'flex', flexDirection: 'column', alignItems: 'center', py: 12, gap: 3, maxWidth: 480, mx: 'auto' }}>
+      <AlertTriangle size={48} color="#c0392b" />
+      <Box sx={{ textAlign: 'center' }}>
+        <Typography variant="h6" sx={{ fontWeight: 600, mb: 1 }}>
+          Analyse fehlgeschlagen
+        </Typography>
+        <Typography variant="body2" color="text.secondary">
+          {message}
+        </Typography>
+      </Box>
+      <Button
+        variant="contained"
+        startIcon={<RotateCcw size={16} />}
+        onClick={onRetry}
+        sx={{ bgcolor: '#1e3a5f', '&:hover': { bgcolor: '#162d4a' } }}
+      >
+        Erneut versuchen
+      </Button>
+    </Box>
+  )
+}