fix(ucca): CM-7 repo_scan is required evidence for attack_surface_minimization

evidence_required lists only required:true rows; repo_scan was required:false so
attack_surface_minimization surfaced config_export alone. An attack-surface scan
IS required to evidence a minimized attack surface. Adds a test pinning the curated
evidence_required set per NIST obligation (the table test only checked control count).

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

ai-compliance-sdk/data/evidence_requirements/nist_evidence.jsonl

@@ -7,4 +7,4 @@
 {"framework": "NIST SP 800-53", "control": "SI-2", "evidence_type": "config_export", "evidence_source": "github", "freshness_requirement": "per_release", "required": true, "rationale": "Konfiguration des sicheren Update-/Patch-Mechanismus (signierte/automatische Updates) als technischer Nachweis.", "version": "2026-06-25"}
 {"framework": "NIST SP 800-53", "control": "SI-2", "evidence_type": "test_report", "evidence_source": "ci", "freshness_requirement": "per_release", "required": true, "rationale": "Update-/Patch-Verifikationstest (CI) belegt, dass Sicherheitsupdates greifen.", "version": "2026-06-25"}
 {"framework": "NIST SP 800-53", "control": "CM-7", "evidence_type": "config_export", "evidence_source": "github", "freshness_requirement": "per_release", "required": true, "rationale": "Konfiguration deaktivierter Ports/Dienste/Funktionen als Nachweis minimierter Angriffsflaeche.", "version": "2026-06-25"}
-{"framework": "NIST SP 800-53", "control": "CM-7", "evidence_type": "repo_scan", "evidence_source": "scanner", "freshness_requirement": "quarterly", "required": false, "rationale": "Angriffsflaechen-Scan (offene Ports/Dienste) — vertiefend, nicht Pflicht je Release.", "version": "2026-06-25"}
+{"framework": "NIST SP 800-53", "control": "CM-7", "evidence_type": "repo_scan", "evidence_source": "scanner", "freshness_requirement": "per_release", "required": true, "rationale": "Angriffsflaechen-Scan (offene Ports/Dienste) als Nachweis tatsaechlich minimierter Angriffsflaeche.", "version": "2026-06-25"}