Rename setSpanKind to setSpanKindOrdinal for clarity

The method sets the cached ordinal, not the string form.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dougqh

dd-trace-core/src/main/java/datadog/trace/core/DDSpanContext.java

@@ -751,7 +751,7 @@ static boolean tagEquals(String tagValue, String tagLiteral) {
    * Cache the span.kind ordinal for fast isOutbound() checks. Called from TagInterceptor when
    * span.kind is set.
    */
-  public void setSpanKind(String kind) {
+  public void setSpanKindOrdinal(String kind) {
     if (kind == null) {
       spanKindOrdinal = SPAN_KIND_UNSET;
     } else if (tagEquals(kind, Tags.SPAN_KIND_SERVER)) {

dd-trace-core/src/main/java/datadog/trace/core/taginterceptor/TagInterceptor.java

@@ -197,7 +197,7 @@ public boolean interceptTag(DDSpanContext span, String tag, Object value) {
       case Tags.SPAN_KIND:
         // Cache the ordinal for fast isOutbound() checks.
         // Return false so the value is still stored in unsafeTags for serialization.
-        span.setSpanKind(String.valueOf(value));
+        span.setSpanKindOrdinal(String.valueOf(value));
         return false;
       default:
         return intercept(span, tag, value);