fix: never rename worktree branches from create_agent path

Auto-naming should only run during worktree creation (mnemonic on create,
async LLM rename moments after). Creating a new agent inside an existing,
properly-named branch must not trigger a rename.

packages/server/src/server/session.ts

@@ -3007,10 +3007,6 @@ export class Session {
       if (!resolvedWorkspace) {
         throw new Error(`Workspace not found: ${msg.workspaceId}`);
       }
-      this.scheduleAutoNameWorkspaceBranchForFirstAgent({
-        workspace: resolvedWorkspace,
-        firstAgentContext,
-      });
       const snapshot = await this.agentManager.createAgent(
         {
           ...sessionConfig,