feat(advisor): evidence-framed header + bindingness contract seam

Rework the Compliance Advisor header ("Diese Antwort stuetzt sich auf")
to describe the EVIDENCE rather than the documents: binding
Rechtsgrundlagen split from Leitlinien (soft-law guidance), a
per-regulation breakdown, plus Abbildungen, Fussnoten and Evidence Units.
No fabricated trust score — objective counts only.

- bindingness is a canonical Legal-KG fact (APEX rule): added an optional
  EvidenceUnit.bindingness contract seam; the FE renders the split from it
  and degrades to a neutral per-regulation breakdown when it is absent
  (SDK/RAG asked via board to populate it in /retrieve).
- evidence-grouping.ts: pure, tested grouping/counting model.
- route.ts: optional `audience` field (tonality) kept out of the retrieval
  question; answers lead with a "Kurz gesagt" summary, structured by theme.
- E2E + unit tests updated for the evidence framing.

Not deployed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

admin-compliance/app/api/sdk/compliance-advisor/chat/route.ts

@@ -45,17 +45,26 @@ folgen belegte Quellen. Wenn der Begriff in mehreren Bereichen vorkommt, erwaehn
 
 const FALLBACK_SYSTEM = `Du bist der BreakPilot Compliance-Berater. Antworte quellenbasiert, verstaendlich und ehrlich auf Deutsch.`
 
+// Optional audience/tonality guidance (e.g. the workspace's role hint). Kept out of the retrieval
+// `question` on purpose — it only shapes the answer's tone, so it belongs in the system prompt.
+function audienceBlock(audience: string): string {
+  return audience ? `\n\n## Ansprache / Zielgruppe\n${audience}` : ''
+}
+
 function answerSystem(
   soul: string | null,
   country: Country | undefined,
   evidenceBlock: string,
   withCitations = true,
+  audience = '',
 ): string {
   let s = soul || FALLBACK_SYSTEM
   if (country) s += countryBlock(country)
+  s += audienceBlock(audience)
   s += `\n\n## Belegte Evidence (nummeriert — DEINE EINZIGEN Quellen)\n${evidenceBlock || '(keine Evidence gefunden)'}`
   s += `\n\n## Antwortformat (WICHTIG)
-- Gut gegliedertes Markdown: kurze ## Ueberschriften je Aspekt, Aufzaehlungen, **Fettung** fuer Kernbegriffe.`
+- Beginne mit einer **Kurzzusammenfassung** (1–2 Saetze, "Kurz gesagt: …"), die den Kern direkt beantwortet.
+- Danach gut gegliedertes Markdown: kurze ## Ueberschriften je THEMA/Aspekt (nicht je Rechtsquelle), Aufzaehlungen, **Fettung** fuer Kernbegriffe.`
   if (withCitations) {
     s += `\n- Belege Kernaussagen mit [n], wobei n die NUMMER der Evidence-Quelle oben ist (z. B. [1], [2]).
 - Nenne KEINE Quellen-/Fundstellen-Liste im Fliesstext — die Quellen werden dem Nutzer separat angezeigt.`
@@ -71,6 +80,7 @@ export async function POST(request: NextRequest) {
     const body = await request.json()
     const question = String(body.question ?? body.message ?? '').trim()
     const context: string | null = body.context ?? null
+    const audience = typeof body.audience === 'string' ? body.audience.trim() : ''
     const country = (['DE', 'AT', 'CH', 'EU'] as const).includes(body.country)
       ? (body.country as Country)
       : undefined
@@ -87,7 +97,7 @@ export async function POST(request: NextRequest) {
       const legacyEvidence = retrieved.evidence ?? []
       const legacySoul = await readSoulFile('compliance-advisor')
       const legacyStream = await streamAdvisorAnswer([
-        { role: 'system', content: answerSystem(legacySoul, country, numberedEvidenceForPrompt(legacyEvidence), false) },
+        { role: 'system', content: answerSystem(legacySoul, country, numberedEvidenceForPrompt(legacyEvidence), false, audience) },
         { role: 'user', content: question },
       ])
       if (!legacyStream) {
@@ -106,7 +116,7 @@ export async function POST(request: NextRequest) {
 
     if (mode === 'clarify') {
       const general = await completeAdvisorAnswer([
-        { role: 'system', content: L1_SYSTEM },
+        { role: 'system', content: L1_SYSTEM + audienceBlock(audience) },
         { role: 'user', content: question },
       ])
       if (general === null) {
@@ -130,7 +140,7 @@ export async function POST(request: NextRequest) {
     const evidence = retrieved.evidence ?? []
     const soul = await readSoulFile('compliance-advisor')
     const messages: ChatMessage[] = [
-      { role: 'system', content: answerSystem(soul, country, numberedEvidenceForPrompt(evidence)) },
+      { role: 'system', content: answerSystem(soul, country, numberedEvidenceForPrompt(evidence), true, audience) },
       { role: 'user', content: question },
     ]
     const answer = await completeAdvisorAnswer(messages)