fix(auth): add undici instrumentation for Squid proxy

Without it, NextAuth's Keycloak issuer-discovery fetch goes direct
and Calico default-deny drops it → /access-denied?error=Configuration.
EnvHttpProxyAgent reads HTTP(S)_PROXY at startup.

Mirrors gscAdmin/src/instrumentation.ts. + undici ^6.25.0.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

k8s/deployment.yaml

@@ -31,7 +31,7 @@ spec:
     spec:
       containers:
         - name: my-ui
-          image: registry.gosec.internal/gsc-my/ui:v0.1.0
+          image: registry.gosec.internal/gsc-my/ui:v0.1.1
           imagePullPolicy: Always
           ports:
             - containerPort: 3000