Add operation types to connection metrics

Connection metrics now include operation type in sql_operation:
- CREATE_SESSION for connection open events
- DELETE_SESSION for connection close events

This matches the proto Operation.Type enum which includes session-level
operations in addition to statement-level operations.

Before:
  sql_operation: null

After:
  sql_operation: {
    statement_type: "CREATE_SESSION"  // or "DELETE_SESSION"
  }

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

Author: samikshya-db

lib/telemetry/DatabricksTelemetryExporter.ts

@@ -319,10 +319,17 @@ export default class DatabricksTelemetryExporter {
 
     // Add metric-specific fields based on proto definition
     if (metric.metricType === 'connection') {
-      // Include connection open latency
+      // Include connection latency
       if (metric.latencyMs !== undefined) {
         log.entry.sql_driver_log.operation_latency_ms = metric.latencyMs;
       }
+
+      // Include operation type (CREATE_SESSION or DELETE_SESSION)
+      if (metric.operationType) {
+        log.entry.sql_driver_log.sql_operation = {
+          statement_type: metric.operationType,
+        };
+      }
     } else if (metric.metricType === 'statement') {
       log.entry.sql_driver_log.operation_latency_ms = metric.latencyMs;
 

lib/telemetry/MetricsAggregator.ts

@@ -142,6 +142,7 @@ export default class MetricsAggregator {
       sessionId: event.sessionId,
       workspaceId: event.workspaceId,
       driverConfig: event.driverConfig,
+      operationType: 'CREATE_SESSION',
       latencyMs: event.latencyMs,
     };
 
@@ -157,6 +158,7 @@ export default class MetricsAggregator {
       timestamp: event.timestamp,
       sessionId: event.sessionId,
       driverConfig: this.driverConfig,
+      operationType: 'DELETE_SESSION',
       latencyMs: event.latencyMs,
     };