Address Copilot review: fix comment accuracy, remove duplicate cause.toString(), update changelog

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jeet1995

sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/http/Http2ParentChannelExceptionHandler.java

@@ -51,14 +51,14 @@ public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
             // (e.g., TCP RST from LB idle timeout, post-close cleanup).
             if (logger.isDebugEnabled()) {
                 logger.debug(
-                    "Exception on HTTP/2 parent connection [id:{}, activeStreams={}, channelActive={}]: {}",
-                    ctx.channel().id().asShortText(), activeStreams, channelActive, cause.toString(), cause);
+                    "Exception on HTTP/2 parent connection [id:{}, activeStreams={}, channelActive={}]",
+                    ctx.channel().id().asShortText(), activeStreams, channelActive, cause);
             }
         } else {
             // Active streams on a live channel — exception may affect in-flight requests.
             logger.warn(
-                "Exception on HTTP/2 parent connection [id:{}, activeStreams={}, channelActive={}]: {}",
-                ctx.channel().id().asShortText(), activeStreams, channelActive, cause.toString(), cause);
+                "Exception on HTTP/2 parent connection [id:{}, activeStreams={}, channelActive={}]",
+                ctx.channel().id().asShortText(), activeStreams, channelActive, cause);
         }
     }
 

sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/http/ReactorNettyClient.java

@@ -171,8 +171,9 @@ private void configureChannelPipelineHandlers() {
                     // In H2, doOnConnected fires for stream (child) channels — channel.parent()
                     // is the TCP connection. The parent pipeline has no ChannelOperationsHandler
                     // (unlike H1.1), so TCP-level exceptions (RST, broken pipe) propagate to
-                    // Netty's TailContext and get logged as WARN. This handler matches H1.1
-                    // behavior by consuming exceptions at DEBUG level.
+                    // Netty's TailContext. This handler aligns the logging with connection state:
+                    // DEBUG when the parent channel is idle or inactive, WARN when the channel
+                    // is active and in-flight streams may be impacted.
                     Channel parent = connection.channel().parent();
                     if (parent != null
                         && parent.pipeline().get(Http2ParentChannelExceptionHandler.HANDLER_NAME) == null) {