[Bug] Schema Registry Overview card shows "Not configured" intermittently despite SR being properly configured

Description

The Schema Registry status card on the Console Overview page intermittently shows "Not configured" even when Schema Registry is properly configured and fully functional (messages are being deserialised correctly using schemas from the registry).

On the same page load, refreshing causes it to alternate between showing the correct count (e.g. 963 schemas) and "Not configured". This is a pure UI reporting bug — the underlying Schema Registry connection works fine.

Root Cause (suspected)

In frontend/src/state/backend-api.ts, the getSchemaRegistryInfo call appears to be gated behind a api.userData?.canViewSchemas permission check. When that flag evaluates to falsy on certain renders/refreshes, the request is skipped entirely, leaving schemaRegistry as null, which causes the Overview card to display "Not configured".

Steps to Reproduce

1. Configure Redpanda Console with a valid Schema Registry URL (e.g. Confluent-compatible kafka-cp-schema-registry).
2. Navigate to the Console Overview page.
3. Observe the Schema Registry card — it may correctly show the schema count (e.g. "963 schemas").
4. Refresh the page.
5. The card now shows "Not configured".
6. Refresh again — it may show the correct count once more.

The flicker is consistent and reproducible across page refreshes in the same session.

Expected Behaviour

The Schema Registry card on the Overview page should consistently display the correct status (schema count and connectivity) whenever SR is configured, regardless of how many times the page is refreshed.

Actual Behaviour

The card alternates between showing the correct schema count and "Not configured" across page refreshes, even though:

• Schema Registry is properly configured in Console's Helm values
• Messages in the topic viewer are being correctly deserialised using schemas from the registry
• The Schema Registry endpoint is reachable and healthy

Environment

• Redpanda Console version: v3.7.1 (chart 3.7.0)
• Schema Registry type: Confluent-compatible (kafka-cp-schema-registry)
• Deployment: Kubernetes (Helm chart, ArgoCD managed)
• Observation: Also co-occurs with issue #2421 (Avro bytes rendering regression), but is an independent bug

Additional Context

• The schema count of 963 is correct when the card does load — confirming the SR endpoint itself is healthy.
• The topic message viewer works correctly (Avro schemas are resolved), confirming the SR connection from Console is functional.
• This appears to be a race condition or permission-flag timing issue in the frontend state management, not a network/infrastructure problem.
• Related to (but independent from): #2421

Start in frontend/src/state/backend-api.ts by reading getSchemaRegistryInfo and the api.userData?.canViewSchemas guard, then reproduce the Overview refresh behavior described in the issue. Done means the Schema Registry card consistently shows its status and schema count when configured, rather than alternating with "Not configured".