Report response latency and errors when using (inline) assistant (#11806)

Release Notes:

- N/A

Co-authored-by: Nathan <nathan@zed.dev>
Co-authored-by: David <davidsp@anthropic.com>

crates/client/src/telemetry.rs

@@ -261,11 +261,15 @@ impl Telemetry {
         conversation_id: Option<String>,
         kind: AssistantKind,
         model: String,
+        response_latency: Option<Duration>,
+        error_message: Option<String>,
     ) {
         let event = Event::Assistant(AssistantEvent {
             conversation_id,
             kind,
             model: model.to_string(),
+            response_latency,
+            error_message,
         });
 
         self.report_event(event)