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/app-server/src/codex_message_processor.rs

@@ -1956,6 +1956,7 @@ impl CodexMessageProcessor {
             approval_policy,
             sandbox,
             config,
+            service_name,
             base_instructions,
             developer_instructions,
             dynamic_tools,
@@ -2023,7 +2024,12 @@ impl CodexMessageProcessor {
 
         match self
             .thread_manager
-            .start_thread_with_tools(config, core_dynamic_tools, persist_extended_history)
+            .start_thread_with_tools_and_service_name(
+                config,
+                core_dynamic_tools,
+                persist_extended_history,
+                service_name,
+            )
             .await
         {
             Ok(new_conv) => {