Add obligation_id join-key contract (cross-session bridge)

Macht meine Seite des Cross-Session-Vertrags konkret: obligation_id ist der stabile Join-Key
zwischen Legal Knowledge Graph (citation_spans -> obligation_id) und Compliance Execution Graph
(control_mapping.source_norm -> obligation_id). Export aller 47 obligation_ids (CRA: 11 sbom +
7 vuln + 29 auth) mit citation_units als Interim-Brücke. Disziplin: obligation_id nie neu
vergeben (re-link, Pendant zu span_id/control_uuid).

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

scripts/obligation_discovery/export_join_keys.py

@@ -0,0 +1,52 @@
+"""Exportiert den OBLIGATION_ID-Join-Key-Vertrag aus den Registry-Artefakten.
+Die obligation_id ist der stabile Brueckenschluessel zwischen Legal Knowledge Graph
+(citation_spans haengen an obligation_id) und Compliance Execution Graph
+(control_mapping.source_norm -> obligation_id). citation_units = die legal_basis-Anker,
+ueber die beide Seiten heute (vor obligation_id-Adoption) bruecken koennen.
+
+DISZIPLIN: obligation_id wird RE-GELINKT, NIE neu vergeben (Pendant zu span_id/control_uuid).
+
+  python3 scripts/obligation_discovery/export_join_keys.py obligations/cra.json obligations/cra_authentication.json
+"""
+from __future__ import annotations
+
+import argparse
+import json
+
+
+def main() -> None:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("registries", nargs="+")
+    ap.add_argument("--out", default="obligations/obligation_join_keys.json")
+    a = ap.parse_args()
+    keys = []
+    for path in a.registries:
+        reg = json.load(open(path, encoding="utf-8"))
+        for o in reg.get("obligations", []):
+            citation_units = [b.get("anchor", "") for b in o.get("legal_basis", []) if b.get("anchor")]
+            keys.append({
+                "obligation_id": o["id"],
+                "regulation": reg.get("regulation", ""),
+                "family": o.get("family", ""),
+                "tier": o.get("tier", ""),
+                "citation_units": citation_units,
+                "source_role": o.get("source_role", ""),
+            })
+    out = {
+        "schema_version": "obligation_join_keys_v1",
+        "contract": "obligation_id ist der stabile Join-Key. Legal Knowledge Graph haengt "
+                    "citation_spans an obligation_id; Compliance Execution Graph mappt "
+                    "control_mapping.source_norm -> obligation_id. Interim-Bruecke = citation_units. "
+                    "obligation_id NIE neu vergeben (re-link).",
+        "count": len(keys),
+        "obligation_ids": keys,
+    }
+    json.dump(out, open(a.out, "w", encoding="utf-8"), ensure_ascii=False, indent=1)
+    from collections import Counter
+    print(f"exportiert: {a.out}  ({len(keys)} obligation_ids)")
+    print("Regulierungen:", dict(Counter(k["regulation"] for k in keys)))
+    print("Familien:", dict(Counter(k["family"] for k in keys)))
+
+
+if __name__ == "__main__":
+    main()