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/page.tsx

@@ -53,6 +53,7 @@ export default function ControlLibraryPage() {
   const [categoryFilter, setCategoryFilter] = useState<string>('')
   const [audienceFilter, setAudienceFilter] = useState<string>('')
   const [sourceFilter, setSourceFilter] = useState<string>('')
+  const [typeFilter, setTypeFilter] = useState<string>('')
   const [sortBy, setSortBy] = useState<'id' | 'newest' | 'oldest' | 'source'>('id')
 
   // CRUD state
@@ -94,10 +95,11 @@ export default function ControlLibraryPage() {
     if (categoryFilter) p.set('category', categoryFilter)
     if (audienceFilter) p.set('target_audience', audienceFilter)
     if (sourceFilter) p.set('source', sourceFilter)
+    if (typeFilter) p.set('control_type', typeFilter)
     if (debouncedSearch) p.set('search', debouncedSearch)
     if (extra) for (const [k, v] of Object.entries(extra)) p.set(k, v)
     return p.toString()
-  }, [severityFilter, domainFilter, stateFilter, verificationFilter, categoryFilter, audienceFilter, sourceFilter, debouncedSearch])
+  }, [severityFilter, domainFilter, stateFilter, verificationFilter, categoryFilter, audienceFilter, sourceFilter, typeFilter, debouncedSearch])
 
   // Load metadata (domains, sources — once + on refresh)
   const loadMeta = useCallback(async () => {
@@ -165,7 +167,7 @@ export default function ControlLibraryPage() {
   useEffect(() => { loadControls() }, [loadControls])
 
   // Reset page when filters change
-  useEffect(() => { setCurrentPage(1) }, [severityFilter, domainFilter, stateFilter, verificationFilter, categoryFilter, audienceFilter, sourceFilter, debouncedSearch, sortBy])
+  useEffect(() => { setCurrentPage(1) }, [severityFilter, domainFilter, stateFilter, verificationFilter, categoryFilter, audienceFilter, sourceFilter, typeFilter, debouncedSearch, sortBy])
 
   // Pagination
   const totalPages = Math.max(1, Math.ceil(totalCount / PAGE_SIZE))
@@ -664,6 +666,15 @@ export default function ControlLibraryPage() {
                 <option key={s.source} value={s.source}>{s.source} ({s.count})</option>
               ))}
             </select>
+            <select
+              value={typeFilter}
+              onChange={e => setTypeFilter(e.target.value)}
+              className="text-sm border border-gray-300 rounded-lg px-2 py-1.5 focus:outline-none focus:ring-2 focus:ring-purple-500"
+            >
+              <option value="">Alle Typen</option>
+              <option value="rich">Rich Controls</option>
+              <option value="atomic">Atomare Controls</option>
+            </select>
             <span className="text-gray-300 mx-1">|</span>
             <ArrowUpDown className="w-4 h-4 text-gray-400" />
             <select