feat: add service name to app-server (#12319)

Add service name to the app-server so that the app can use it's own
service name

This is on thread level because later we might plan the app-server to
become a singleton on the computer

codex-rs/otel/src/lib.rs

@@ -45,6 +45,7 @@ pub struct OtelEventMetadata {
     pub(crate) account_id: Option<String>,
     pub(crate) account_email: Option<String>,
     pub(crate) originator: String,
+    pub(crate) service_name: Option<String>,
     pub(crate) session_source: String,
     pub(crate) model: String,
     pub(crate) slug: String,
@@ -67,6 +68,11 @@ impl OtelManager {
         self
     }
 
+    pub fn with_metrics_service_name(mut self, service_name: &str) -> Self {
+        self.metadata.service_name = Some(sanitize_metric_tag_value(service_name));
+        self
+    }
+
     pub fn with_metrics(mut self, metrics: MetricsClient) -> Self {
         self.metrics = Some(metrics);
         self.metrics_use_metadata_tags = true;
@@ -197,7 +203,7 @@ impl OtelManager {
         if !self.metrics_use_metadata_tags {
             return Ok(Vec::new());
         }
-        let mut tags = Vec::with_capacity(6);
+        let mut tags = Vec::with_capacity(7);
         Self::push_metadata_tag(&mut tags, "auth_mode", self.metadata.auth_mode.as_deref())?;
         Self::push_metadata_tag(
             &mut tags,
@@ -209,6 +215,11 @@ impl OtelManager {
             "originator",
             Some(self.metadata.originator.as_str()),
         )?;
+        Self::push_metadata_tag(
+            &mut tags,
+            "service_name",
+            self.metadata.service_name.as_deref(),
+        )?;
         Self::push_metadata_tag(&mut tags, "model", Some(self.metadata.model.as_str()))?;
         Self::push_metadata_tag(&mut tags, "app.version", Some(self.metadata.app_version))?;
         Ok(tags)

codex-rs/otel/src/traces/otel_manager.rs

@@ -79,6 +79,7 @@ impl OtelManager {
                 account_id,
                 account_email,
                 originator: sanitize_metric_tag_value(originator.as_str()),
+                service_name: None,
                 session_source: session_source.to_string(),
                 model: model.to_owned(),
                 slug: slug.to_owned(),