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/tables/LoadingRows.tsx

@@ -0,0 +1,22 @@
+import { Skeleton, TableCell, TableRow } from '@mui/material'
+
+interface LoadingRowsProps {
+  rows?: number
+  cols?: number
+}
+
+export function LoadingRows({ rows = 5, cols = 6 }: LoadingRowsProps) {
+  return (
+    <>
+      {Array.from({ length: rows }).map((_, ri) => (
+        <TableRow key={ri}>
+          {Array.from({ length: cols }).map((_, ci) => (
+            <TableCell key={ci}>
+              <Skeleton variant="text" height={18} width={ci === 0 ? '80%' : ci === cols - 1 ? '40%' : '65%'} />
+            </TableCell>
+          ))}
+        </TableRow>
+      ))}
+    </>
+  )
+}