[Cloud Shell] API Error: "Requested entity was not found" when using Lab Accounts in

### What happened?

When using the Gemini CLI using a Google Cloud Lab, the tool fails to execute commands and returns an API error, despite the CLI being actively promoted to the user within the Cloud Shell environment.

### What did you expect to happen?

Error message:
`✕ [API Error: Requested entity was not found.]`

### What did you expect to happen?
The CLI should authenticate and execute queries successfully using the default credentials provided by the Cloud Shell environment, regardless of whether it is a standard or lab-based account.

### Client information

* **CLI Version:** 0.23.0
* **Git Commit:** 3ff055840
* **Model:** auto-gemini-3
* **OS:** Linux (Cloud Shell)
* **GCP Project:** cloudshell-gca

### Login information

Auth Method: `compute-default-credentials` (Standard Cloud Shell environment login).

### Anything else we need to know?

The `/about` command output confirms the CLI is picking up `compute-default-credentials`, but it seems the specific project `cloudshell-gca` or the lab service account may lack the necessary permissions or API enablement that the CLI expects.