chore(otlp): restore explanatory comments for stats processing

Address PR review feedback:
- Restore comment explaining stats must be computed after obfuscation
- Add comment explaining stats errors are non-critical and logged only

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: jchrostek-dd

bottlecap/src/otlp/agent.rs

@@ -204,9 +204,13 @@ impl Agent {
             }
         }
 
+        // This needs to be after process_traces() because process_traces()
+        // performs obfuscation, and we need to compute stats on the obfuscated traces.
         if compute_trace_stats_on_extension
             && let Err(err) = stats_generator.send(&processed_traces)
         {
+            // Just log the error. We don't think trace stats are critical, so we don't want to
+            // return an error if only stats fail to send.
             error!("OTLP | Error sending traces to the stats concentrator: {err}");
         }
 

bottlecap/src/otlp/grpc_agent.rs

@@ -80,9 +80,12 @@ impl TraceService for OtlpGrpcService {
             debug!("OTLP gRPC | Successfully buffered traces to be aggregated.");
         }
 
+        // Compute stats after process_traces() which performs obfuscation.
         if compute_trace_stats_on_extension
             && let Err(err) = self.stats_generator.send(&processed_traces)
         {
+            // Just log the error. We don't think trace stats are critical, so we don't want to
+            // return an error if only stats fail to send.
             error!("OTLP gRPC | Error sending traces to the stats concentrator: {err}");
         }