test(settings): cover the new float setting type in the defaults audit

TestSettingDefaults enumerates registry types; 'float' hit the unknown-
type branch. Added float validation (default parses, within [min,max])
mirroring the int case.

internal/database/settings_registry_test.go

@@ -36,6 +36,21 @@ func TestSettingDefaults(t *testing.T) {
 			if _, err := strconv.ParseBool(d.Value); err != nil {
 				t.Errorf("bool setting %s default %q is not a bool", d.Key, d.Value)
 			}
+		case SettingTypeFloat:
+			f, err := strconv.ParseFloat(d.Value, 64)
+			if err != nil {
+				t.Errorf("float setting %s default %q is not a float", d.Key, d.Value)
+			}
+			if d.Min != "" {
+				if mn, err := strconv.ParseFloat(d.Min, 64); err == nil && f < mn {
+					t.Errorf("float setting %s default %q below min %q", d.Key, d.Value, d.Min)
+				}
+			}
+			if d.Max != "" {
+				if mx, err := strconv.ParseFloat(d.Max, 64); err == nil && f > mx {
+					t.Errorf("float setting %s default %q above max %q", d.Key, d.Value, d.Max)
+				}
+			}
 		case SettingTypeString:
 			if d.Value == "" {
 				t.Errorf("string setting %s has empty default", d.Key)