feat(licenses): attribution renderer — Stufe 1 (overview) + Stufe 3 (SourceBadge)

Backend
- backend-compliance/compliance/api/licenses_routes.py: three endpoints
  built on the now-complete license_rule classification
  - GET  /api/compliance/licenses/overview
       global aggregation by rule + per-source breakdown (Stufe 1)
  - POST /api/compliance/licenses/aggregate
       per-control-set aggregation for PDF footer (Stufe 2) and
       tech-file appendix (Stufe 4) — consumed later
  - GET  /api/compliance/licenses/source-info/{control_uuid}
       single-control lookup for the inline source badge (Stufe 3)
- registered in api/__init__.py via the existing safe-import loader

Frontend
- app/sdk/licenses/page.tsx (Stufe 1): the /sdk/licenses overview page.
  Renders rule legend cards + per-rule source tables. Drives the
  /licenses footer link and gives auditors a one-page view of what
  licence classes the platform is operating under.
- components/sdk/SourceBadge.tsx (Stufe 3): reusable React component.
  Small R1/R2/R3 pill with click-expand tooltip showing source
  regulation + attribution string + render-full-text policy. Will be
  embedded into IACE hazards/mitigations, VVT items, DSFA controls in
  follow-up commits.

Two stages of the four-stage renderer are now ready. Stufe 2 (PDF
auto-footer) + Stufe 4 (tech-file appendix) follow once the existing
PDF generators are extended to call /licenses/aggregate.

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

@@ -0,0 +1,160 @@
+'use client'
+
+import { useEffect, useState } from 'react'
+
+// Stufe 1 of the Attribution Renderer (Task #23): the global
+// "Quellen & Lizenzen" overview. Aggregates all 314k canonical_controls
+// by their license_rule and shows the source regulations behind each
+// bucket. Drives the footer link and gives auditors a one-page view of
+// what licence classes the platform is operating under.
+
+type SourceCount = {
+  regulation_id: string
+  regulation_name_de: string | null
+  license_rule: number
+  license_type: string | null
+  attribution: string | null
+  jurisdiction: string | null
+  source_type: string | null
+  n_controls: number
+}
+
+type RuleBucket = {
+  rule: number
+  label_de: string
+  label_en: string
+  attribution_required: boolean
+  render_full_text: boolean
+  total_controls: number
+  distinct_sources: number
+  sources: SourceCount[]
+}
+
+type Overview = {
+  total_controls: number
+  buckets: RuleBucket[]
+}
+
+const RULE_COLOR: Record<number, string> = {
+  1: 'border-emerald-200 bg-emerald-50',
+  2: 'border-amber-200 bg-amber-50',
+  3: 'border-slate-200 bg-slate-50',
+}
+
+const RULE_BADGE: Record<number, string> = {
+  1: 'bg-emerald-600 text-white',
+  2: 'bg-amber-600 text-white',
+  3: 'bg-slate-600 text-white',
+}
+
+export default function LicensesPage() {
+  const [data, setData] = useState<Overview | null>(null)
+  const [error, setError] = useState<string | null>(null)
+
+  useEffect(() => {
+    fetch('/api/sdk/v1/compliance/licenses/overview')
+      .then((r) => (r.ok ? r.json() : Promise.reject(`HTTP ${r.status}`)))
+      .then(setData)
+      .catch((e) => setError(String(e)))
+  }, [])
+
+  if (error) {
+    return (
+      <div className="p-6">
+        <h1 className="text-xl font-semibold mb-2">Quellen &amp; Lizenzen</h1>
+        <p className="text-red-600">Fehler beim Laden: {error}</p>
+      </div>
+    )
+  }
+  if (!data) {
+    return (
+      <div className="p-6">
+        <h1 className="text-xl font-semibold">Quellen &amp; Lizenzen</h1>
+        <p className="text-slate-500 mt-2">Lade …</p>
+      </div>
+    )
+  }
+
+  return (
+    <div className="p-6 max-w-7xl">
+      <header className="mb-6">
+        <h1 className="text-2xl font-semibold">Quellen &amp; Lizenzen</h1>
+        <p className="text-sm text-slate-600 mt-1">
+          Diese Plattform stützt sich auf {data.total_controls.toLocaleString('de-DE')}{' '}
+          klassifizierte Compliance-Controls aus den unten genannten Quellen.
+          Jeder Control trägt eine deterministische Lizenzregel (R1–R3), die das
+          Render-Verhalten in Berichten und im Frontend steuert.
+        </p>
+      </header>
+
+      <section className="mb-8">
+        <h2 className="text-lg font-medium mb-3">Klassifizierungs-Schema</h2>
+        <div className="grid grid-cols-1 md:grid-cols-3 gap-3 text-sm">
+          {data.buckets.map((b) => (
+            <div key={b.rule} className={`rounded border ${RULE_COLOR[b.rule] ?? 'border-slate-200'} p-3`}>
+              <div className="flex items-center gap-2 mb-2">
+                <span className={`inline-flex items-center justify-center w-7 h-7 rounded-full text-xs font-bold ${RULE_BADGE[b.rule] ?? 'bg-slate-600 text-white'}`}>
+                  R{b.rule}
+                </span>
+                <span className="font-medium">{b.label_de}</span>
+              </div>
+              <ul className="text-xs text-slate-700 space-y-1">
+                <li>{b.total_controls.toLocaleString('de-DE')} Controls</li>
+                <li>{b.distinct_sources} Quellen</li>
+                <li>{b.render_full_text ? 'Volltext-Anzeige erlaubt' : 'Nur Identifier-Verweis'}</li>
+                <li>{b.attribution_required ? 'Attribution-Pflicht in Output' : 'keine Attribution-Pflicht'}</li>
+              </ul>
+            </div>
+          ))}
+        </div>
+      </section>
+
+      {data.buckets.map((b) => (
+        <section key={b.rule} className="mb-8">
+          <h2 className="text-lg font-medium mb-3 flex items-center gap-2">
+            <span className={`inline-flex items-center justify-center w-7 h-7 rounded-full text-xs font-bold ${RULE_BADGE[b.rule] ?? 'bg-slate-600 text-white'}`}>
+              R{b.rule}
+            </span>
+            {b.label_de}{' '}
+            <span className="text-sm text-slate-500 font-normal">
+              ({b.total_controls.toLocaleString('de-DE')} Controls aus {b.distinct_sources} Quellen)
+            </span>
+          </h2>
+
+          <div className="overflow-x-auto border rounded">
+            <table className="w-full text-sm">
+              <thead className="bg-slate-100 text-slate-700">
+                <tr>
+                  <th className="text-left p-2">Quelle</th>
+                  <th className="text-left p-2">Lizenztyp</th>
+                  <th className="text-left p-2">Rechtsraum</th>
+                  <th className="text-left p-2">Attribution</th>
+                  <th className="text-right p-2">Controls</th>
+                </tr>
+              </thead>
+              <tbody>
+                {b.sources.map((s) => (
+                  <tr key={`${b.rule}-${s.regulation_id}`} className="border-t">
+                    <td className="p-2">{s.regulation_name_de ?? s.regulation_id}</td>
+                    <td className="p-2 text-slate-600">{s.license_type ?? '—'}</td>
+                    <td className="p-2 text-slate-600">{s.jurisdiction ?? '—'}</td>
+                    <td className="p-2 text-slate-600">{s.attribution ?? '—'}</td>
+                    <td className="p-2 text-right tabular-nums">{s.n_controls.toLocaleString('de-DE')}</td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        </section>
+      ))}
+
+      <footer className="text-xs text-slate-500 border-t pt-4 mt-8">
+        Klassifizierung: deterministisch über parent_control_uuid-Vererbung,
+        control_parent_links → regulation_registry, source_citation,
+        canonical_processed_chunks (Pipeline-Ground-Truth) und LLM-Aggregat-
+        Identifikation für eigene Werke. Audit-Skripte unter
+        breakpilot-core/control-pipeline/scripts/.
+      </footer>
+    </div>
+  )
+}