### Summary
Authorino logs show CEL expression evaluation failures (`"no such key: identity"`) when evaluating TelemetryPolicy metric labels. This is *expected behavior* due to the timing of when expressions are evaluated in the Gateway-Authorino interaction flow, not an actual error.

### Problem Statement
When using TelemetryPolicy with metric labels that reference `auth.identity.*` fields (e.g., `auth.identity.userid`, `auth.identity.tier`), Authorino logs show errors like:

```
"msg": "failed to evaluate CEL expression",
"expression": "auth.identity.userid",
"error": "no such key: identity"
```

### Root Cause
The error occurs due to a *timing and context issue* in the request processing pipeline:

1. *Premature Evaluation*: The Gateway forwards unevaluated CEL label expressions (e.g., `"auth.identity.userid"`) to Authorino before the authentication context is fully established.

2. *Missing Context*: Authorino attempts to evaluate these expressions immediately, but at that point in the processing pipeline, the `identity` context has not yet been populated. The authentication process hasn't completed, so the identity mapping doesn't exist yet.

3. *Successful Resolution*: After Authorino processes the authentication request and returns a successful response (with identity data populated from the AuthPolicy), the Gateway re-evaluates the metric labels correctly and sends them to Limitador/Prometheus.

### Expected Behavior
- *Authorino logs the failure* because it tries to evaluate the label expressions too early in the pipeline
- *The Gateway successfully handles it* afterwards using Authorino's response
- *Limitador metrics are correctly populated* with user and tier information
- *This is not a bug* - it's the expected flow of how the Gateway and Authorino interact

### Impact
- *Low*: No functional impact - metrics are correctly populated despite the log messages
- *Medium*: Log noise can be confusing for operators debugging issues
- The error messages in logs may cause unnecessary concern or investigation

### Proposed Solution / Improvement
Consider improving Authorino's logging behavior to:
- Ignore metric label expressions that cannot be evaluated at Authorino's evaluation stage
- Log at DEBUG level instead of ERROR/WARN for these expected timing-related evaluation failures
- Add documentation clarifying this is expected behavior

### Related Components
- Kuadrant Gateway
- Authorino (authentication service)
- TelemetryPolicy
- Limitador (rate limiting service)
- Prometheus metrics

### References

• https://gist.github.com/nerdalert/bf852e4949b0316c78dcf3442bcc275f
• https://gist.github.com/nerdalert/d49139e7e80dd4b6ab662315fd22b384