Fix sync loader spinner showing for initializing (non-running) agents

Initializing agents were mapped to the "running" bucket in both server
and client, causing the SyncedLoader spinner to appear in tabs and
sidebar workspace rows when opening an agent for the first time.

packages/server/src/server/session.ts

@@ -5322,7 +5322,7 @@ export class Session {
     if (agent.status === "error" || agent.attentionReason === "error") {
       return "failed";
     }
-    if (agent.status === "running" || agent.status === "initializing") {
+    if (agent.status === "running") {
       return "running";
     }
     if (agent.requiresAttention) {