feat: control_parent_links population + traceability API + frontend

- _write_atomic_control() now uses RETURNING id and inserts into
  control_parent_links (M:N) with source_regulation, source_article,
  and obligation_candidate_id parsed from parent's source_citation
- New _parse_citation() helper for JSONB source_citation extraction
- New GET /controls/{id}/traceability endpoint returning full chain:
  parent links with obligations, child controls, source_count
- Backend: control_type filter (atomic/rich) for controls + count
- Frontend: Rechtsgrundlagen section in ControlDetail showing all
  parent links per source regulation with obligation text + strength
- Frontend: Atomic/Rich filter dropdown in Control Library list
- Frontend: GenerationStrategyBadge recognizes 'pass0b' strategy
- Tests: 3 new tests for parent_link creation + citation parsing,
  existing batch test mock updated for RETURNING clause

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

admin-compliance/app/sdk/control-library/components/helpers.tsx

@@ -282,7 +282,7 @@ export function GenerationStrategyBadge({ strategy }: { strategy: string | null
   if (strategy === 'phase74_gap_fill') {
     return <span className="inline-flex items-center px-1.5 py-0.5 rounded text-xs font-medium bg-blue-100 text-blue-700">v5 Gap</span>
   }
-  if (strategy === 'pass0b_atomic') {
+  if (strategy === 'pass0b_atomic' || strategy === 'pass0b') {
     return <span className="inline-flex items-center px-1.5 py-0.5 rounded text-xs font-medium bg-violet-100 text-violet-700">Atomar</span>
   }
   return <span className="inline-flex items-center px-1.5 py-0.5 rounded text-xs font-medium bg-gray-100 text-gray-500">{strategy}</span>