feat(use-case-controls): relevant als Stufe statt Hard-Filter + Provenance

Der harte relevant=true-Filter versteckte ~25% des Korpus (40.926 Atome),
~70% davon echte Pflichten (500er-Validierung). relevant wird zur Stufe:

- Service: tier-Param (core=Default schuetzt Agent/CRA; all=alles inkl. review),
  ORDER BY relevant DESC; pro Control relevant/tier/source_type
  (own_library bei license_rule=3, sonst derived) + source_regulation/article;
  core_count/review_count. Pure Helper tier_label + source_type (+ Tests).
- Route: optionaler tier-Query (default core) — contract-safe (additiv).
- Frontend: Coverage-Drill-down /sdk/coverage/[useCase] — Kern-Pflichten vs.
  "zur fachlichen Pruefung", je mit Herkunfts-Badge; Uebersicht zeigt Delta.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

admin-compliance/app/sdk/coverage/page.tsx

@@ -1,3 +1,4 @@
+import Link from 'next/link'
 import {
   type UseCaseRow,
   type CorpusOverview,
@@ -47,6 +48,7 @@ export default async function CoveragePage() {
   const groups = groupUseCases(useCases)
   const totalRelevant = useCases.reduce((s, u) => s + u.atom_relevant, 0)
   const totalAtoms = useCases.reduce((s, u) => s + u.atom_total, 0)
+  const totalReview = totalAtoms - totalRelevant
 
   return (
     <div className="mx-auto max-w-7xl space-y-10 p-6">
@@ -62,8 +64,8 @@ export default async function CoveragePage() {
 
       <section className="grid grid-cols-2 gap-3 sm:grid-cols-4">
         <Stat label="Use Cases" value={useCases.length} />
-        <Stat label="Pflichten (relevant)" value={totalRelevant.toLocaleString('de-DE')} />
-        <Stat label="klassifizierte Atome" value={totalAtoms.toLocaleString('de-DE')} />
+        <Stat label="Kern-Pflichten" value={totalRelevant.toLocaleString('de-DE')} />
+        <Stat label="zur Prüfung" value={totalReview.toLocaleString('de-DE')} />
         <Stat label="Quell-Dokumente" value={corpus?.totals.documents ?? 0} />
       </section>
 
@@ -104,19 +106,30 @@ export default async function CoveragePage() {
                   <tr>
                     <th className="px-4 py-2">Use Case</th>
                     <th className="px-4 py-2">Key</th>
-                    <th className="px-4 py-2 text-right">relevant</th>
-                    <th className="px-4 py-2 text-right">klassifiziert</th>
+                    <th className="px-4 py-2 text-right">Kern</th>
+                    <th className="px-4 py-2 text-right">zur Prüfung</th>
+                    <th className="px-4 py-2 text-right">gesamt</th>
                     <th className="px-4 py-2">Quellen</th>
                   </tr>
                 </thead>
                 <tbody className="divide-y divide-gray-100 bg-white">
                   {g.rows.map((u) => (
-                    <tr key={u.key} className={u.atom_relevant === 0 ? 'text-gray-400' : ''}>
-                      <td className="px-4 py-2 font-medium text-gray-900">{u.label}</td>
+                    <tr key={u.key} className={u.atom_total === 0 ? 'text-gray-400' : ''}>
+                      <td className="px-4 py-2 font-medium">
+                        <Link
+                          href={`/sdk/coverage/${u.key}`}
+                          className="text-purple-700 hover:underline"
+                        >
+                          {u.label}
+                        </Link>
+                      </td>
                       <td className="px-4 py-2 font-mono text-xs text-gray-500">{u.key}</td>
                       <td className="px-4 py-2 text-right font-semibold">
                         {u.atom_relevant.toLocaleString('de-DE')}
                       </td>
+                      <td className="px-4 py-2 text-right text-amber-700">
+                        {(u.atom_total - u.atom_relevant).toLocaleString('de-DE')}
+                      </td>
                       <td className="px-4 py-2 text-right text-gray-500">
                         {u.atom_total.toLocaleString('de-DE')}
                       </td>