chore(llmobs): add enable and disable debug logs (#5987)

* add enablement/disable logs

Author: sabrenner

packages/dd-trace/src/llmobs/index.js

@@ -22,6 +22,8 @@ const LLMObsTagger = require('./tagger')
 const LLMObsSpanWriter = require('./writers/spans')
 const { setAgentStrategy } = require('./writers/util')
 
+const util = require('node:util')
+
 /**
  * Setting writers and processor globally when LLMObs is enabled
  * We're setting these in this module instead of on the SDK.
@@ -75,6 +77,7 @@ function enable (config) {
     spanWriter?.setAgentless(useAgentless)
 
     telemetry.recordLLMObsEnabled(startTime, config)
+    log.debug(`[LLMObs] Enabled LLM Observability with configuration: ${util.inspect(config.llmobs)}`)
   })
 }
 
@@ -90,6 +93,8 @@ function disable () {
 
   spanWriter = null
   evalWriter = null
+
+  log.debug('[LLMObs] Disabled LLM Observability')
 }
 
 // since LLMObs traces can extend between services and be the same trace,