feat(design-system): F003 – complete design system foundation

Design tokens:
- lib/ds.ts: DS_COLORS (resultType/confidence/risk/availability/freshness/dataQuality), scoreToConfidenceLevel(), scoreToDataQualityLevel()
- lib/constants.ts: added CONFIDENCE_LABELS, DATA_QUALITY_LABELS

Badge system (src/components/badges/):
- ResultTypeBadge, ConfidenceBadge, RiskBadge, AvailabilityBadge, FreshnessBadge, DataQualityBadge
- All use DS_COLORS, MUI Chip size=small, lucide icons, German labels from constants

Score components (src/components/scores/):
- ConfidenceScore: numeric % with color from utils.confidenceHex
- DataQualityScore: LinearProgress + qualitative label
- ScoreBar: horizontal bar with label/value/weight
- ScoreBreakdownMini: ScoreFactor[] mapped to ScoreBars with Tooltip explanations

Card system (src/components/cards/):
- DecisionCard: header+badges+score+body+actions, selected/loading/restricted states
- CompactCard: single-row 48px card with leading/trailing slots
- MetricCard: KPI card with label/value/delta/icon (extracted pattern from SupplyDashboard)

Panel system (src/components/panels/):
- InfoPanel: outlined Paper with icon+title header
- DetailPanel: Accordion sections in bordered Paper
- WarningPanel: MUI Alert with warning/critical severity

Table components (src/components/tables/):
- DataTableShell: Paper+TableContainer+Table with loading/empty/toolbar slots
- TableToolbar: flex row with title/count/filters/actions
- FilterBar: deletable Chips with clear-all
- EmptyTableState: centered empty row spanning all cols
- LoadingRows: Skeleton cell rows

Form components (src/components/forms/):
- TextInput: MUI TextField wrapper with onChange(string) signature
- SelectField: generic SelectField<T extends string> with MUI Select
- PriorityChipGroup: togglable Chip set (single/multi select)
- FieldWithConfidence: label+value+ConfidenceBadge for AI-parsed fields

UI additions (src/components/ui/):
- CardSkeleton, PanelLoadingState, UnauthorizedState, RestrictedState

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

src/components/badges/FreshnessBadge.tsx

@@ -0,0 +1,37 @@
+import { Chip } from '@mui/material'
+import { Zap, Clock, AlertCircle } from 'lucide-react'
+import type { FreshnessStatus } from '../../domain/enums'
+import { DS_COLORS } from '../../lib/ds'
+import { FRESHNESS_LABELS } from '../../lib/constants'
+
+interface FreshnessBadgeProps {
+  status: FreshnessStatus
+  size?: 'small' | 'medium'
+}
+
+const ICONS: Record<FreshnessStatus, React.ElementType> = {
+  FRESH:    Zap,
+  STALE:    Clock,
+  OUTDATED: AlertCircle,
+}
+
+export function FreshnessBadge({ status, size = 'small' }: FreshnessBadgeProps) {
+  const { bg, fg } = DS_COLORS.freshness[status]
+  const Icon = ICONS[status]
+  return (
+    <Chip
+      size={size}
+      label={FRESHNESS_LABELS[status] ?? status}
+      icon={<Icon size={11} color={fg} />}
+      aria-label={`Datenaktualität: ${FRESHNESS_LABELS[status] ?? status}`}
+      sx={{
+        bgcolor: bg,
+        color: fg,
+        border: 'none',
+        fontWeight: 600,
+        fontSize: '0.7rem',
+        '& .MuiChip-icon': { ml: 0.5 },
+      }}
+    />
+  )
+}