feat(ai-sdk): control-intent result diversity + standard-name classifier override

On an implementation question impl_guidance (ENISA) keeps its earned semantic
Top-1, but the top-K now surfaces the best operational_requirement and
control_standard from the pool (ensureControlDiversity) — so different source
roles are visible instead of one role flooding the list, without forcing the
binding sources to Top-1.

A recognised standard NAME (NIST/OWASP/ISO 27001/CIS/CSA CCM/Grundschutz) now
overrides a mis-applied supervisory_guidance source_class in classifyAuthority,
so those standards classify and rank as technical_standard (control_standard
role). The corpus tags many standards as guidance (weight 70); the name wins.

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

ai-compliance-sdk/internal/ucca/control_role_test.go

@@ -77,3 +77,58 @@ func TestControlRoleOf_Payload(t *testing.T) {
 		t.Errorf("DORA abstract article role = %q must be excluded from the control-pool", got)
 	}
 }
+
+func headHasRole(head []LegalSearchResult, role string) bool {
+	for _, r := range head {
+		if classifyRole(r) == role {
+			return true
+		}
+	}
+	return false
+}
+
+func TestEnsureControlDiversity(t *testing.T) {
+	ig := func(n string) LegalSearchResult {
+		return LegalSearchResult{RegulationShort: "ENISA " + n + " Good Practices"}
+	}
+	opReq := LegalSearchResult{RegulationShort: "CRA", ArticleLabel: "CRA Anhang I", Category: "regulation"}
+	std := LegalSearchResult{RegulationShort: "NIST SP 800-53"}
+
+	t.Run("injects missing op_req + control_standard, guidance keeps Top-1", func(t *testing.T) {
+		out := ensureControlDiversity([]LegalSearchResult{ig("A"), ig("B"), ig("C"), std, opReq}, 3)
+		head := out[:3]
+		if classifyRole(head[0]) != roleImplGuidance {
+			t.Errorf("Top-1 should stay implementation_guidance, got %q", classifyRole(head[0]))
+		}
+		if !headHasRole(head, roleOperationalReq) {
+			t.Error("top-K must contain an operational_requirement after diversity")
+		}
+		if !headHasRole(head, roleControlStandard) {
+			t.Error("top-K must contain a control_standard after diversity")
+		}
+	})
+
+	t.Run("no-op when both roles already present", func(t *testing.T) {
+		out := ensureControlDiversity([]LegalSearchResult{opReq, std, ig("A"), ig("B")}, 3)
+		if classifyRole(out[0]) != roleOperationalReq || classifyRole(out[1]) != roleControlStandard {
+			t.Error("already-diverse top-K must be left untouched")
+		}
+	})
+
+	t.Run("absent role is not forced (no panic)", func(t *testing.T) {
+		out := ensureControlDiversity([]LegalSearchResult{ig("A"), ig("B"), ig("C"), std}, 3)
+		if !headHasRole(out[:3], roleControlStandard) {
+			t.Error("present control_standard should be injected")
+		}
+		if headHasRole(out[:3], roleOperationalReq) {
+			t.Error("operational_requirement absent from the pool must NOT appear")
+		}
+	})
+
+	t.Run("topK covering the whole pool is unchanged", func(t *testing.T) {
+		out := ensureControlDiversity([]LegalSearchResult{ig("A"), opReq}, 5)
+		if len(out) != 2 || classifyRole(out[0]) != roleImplGuidance {
+			t.Error("topK >= len must return results unchanged")
+		}
+	})
+}