[Bug] Unstable authentication behavior in DevLake's built-in Grafana

### [Title] Unstable authentication behavior in DevLake's built-in Grafana
### [Description]
There are no issues when connecting DevLake servers with an external Grafana instance for authentication. However, when using the **built-in Grafana**, the authentication behavior appears to be highly unstable.
The reasons for this assumption are detailed below:
#### 1. Initial admin password change triggers authentication errors in logs
When logging in with the default admin password of the built-in Grafana, I can successfully set a new password (e.g., qwer1234!@#$zxcv). Although the login itself succeeds at this moment, the following error logs are generated simultaneously:
```
logger=authn.service t=2026-06-01T01:17:51.799849464Z level=info msg="Failed to authenticate request" client=auth.client.basic error="[password-auth.failed] too many consecutive incorrect login attempts for user - login for user temporarily blocked"

logger=authn.service t=2026-06-01T01:26:25.203763833Z level=info msg="Failed to authenticate request" client=auth.client.basic error="[password-auth.failed] failed to authenticate identity: [password-auth.invalid] invalid password"

```
#### 2. Creating a new user blocks the Admin account
Immediately after creating a new user within Grafana, the admin account is suddenly locked out and can no longer log in.
#### 3. CLI Admin password reset does not work
Even after resetting the admin password via the CLI, the login still fails.
#### 4. Restarting the Grafana container/service yields the same result
Restarting Grafana does not resolve the issue, and the authentication failure persists.
Could anyone please look into what might be causing this behavior in the built-in Grafana setup? Any insights or workarounds would be greatly appreciated.
#### 5. Settings
```
## DevLake Grafana
grafana:
enabled: true

deploymentStrategy:
type: Recreate
adminPassword: ""
grafana.ini:
server:
serve_from_subpath: "true"
root_url: "%(protocol)s://%(domain)s/grafana"
```