Add SessionStorageConfig to pkg/vmcp/config.Config and populate it in
the VirtualMCPServer converter when spec.sessionStorage.provider is
"redis". This allows vMCP pods to discover Redis connection parameters
(address, db, keyPrefix) at startup via the existing config injection
path. The Redis password is excluded from the config type and is
injected separately as the THV_SESSION_REDIS_PASSWORD environment
variable by the deployment builder.

Closes: #4214

Unit tests (controllers package):
- TestConfigMapContent_SessionStorage: verifies that ensureVmcpConfigConfigMap
  produces a ConfigMap YAML with the sessionStorage section populated when
  provider=redis, and absent when nil or memory.
- TestDeploymentForVirtualMCPServer_WithRedisPassword: verifies that
  deploymentForVirtualMCPServer injects THV_SESSION_REDIS_PASSWORD as a
  SecretKeyRef env var and never as a plaintext value.

Integration tests (envtest with real CRDs + controller loop):
- MCPServer: ScalingConfig (backend_replicas + session_redis) is written to
  the RunConfig ConfigMap when backendReplicas and Redis sessionStorage are
  set; omitted when absent.
- VirtualMCPServer: spec.replicas is reflected in Deployment.Spec.Replicas;
  nil replicas produces a nil Deployment replicas field for HPA compatibility.

E2E tests (Kind cluster via thv-operator-e2e-test-run):
- VirtualMCPServer created with replicas=2 runs 2 ready pods and sets
  SessionStorageWarning condition when no Redis is configured.
- Scale lifecycle (1→2→1): verifies Deployment replicas update in-place,
  2 pods come up, SessionStorageWarning fires on scale-up and clears on
  scale-down.

Closes: #4220

Fix ignored AddToScheme errors in unit tests

Replace `_ = *.AddToScheme(scheme)` with `require.NoError(t, *.AddToScheme(scheme))`
in virtualmcpserver_deployment_test.go and virtualmcpserver_vmcpconfig_test.go so
that scheme registration failures cause an immediate, clear test failure rather than
a confusing error later with a partially configured scheme.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

…ation

Annotation changes do not increment metadata.generation on Kubernetes resources.
The previous trigger used `vmcp.Annotations["test/trigger-reconcile"] = "true"`,
which left generation unchanged, so `triggerGeneration = vmcp.Generation + 1`
was always one ahead of ObservedGeneration and the Eventually timed out.

Fix: trigger via `vmcp.Spec.ServiceType = "ClusterIP"` (the default value,
semantically a no-op) which IS a spec change and DOES increment Generation.
After the Update, controller-runtime populates the object in-place with the
server response, so `vmcp.Generation` is already the post-increment value.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>