fix(traefik): remove invalid controllerName flag causing CrashLoopBackOff (#136)

## URGENT — Traefik pods are CrashLoopBackOff

The merged PR #135 added `--providers.kubernetesgateway.controllerName` as an `additionalArguments` entry. Traefik v3.7.0 does not support this flag and fails immediately on startup.

Old replica sets are still running (one pod each) but new pods cannot come up.

## Fix

- Remove `additionalArguments` from both `values-internal.yaml` and `values-external.yaml`
- Revert GatewayClass `controllerName` back to `traefik.io/gateway-controller` (the hardcoded Traefik default — no override mechanism exists in v3.7.0)

## After merge

GatewayClasses will remain `Unknown` until a separate solution for internal/external separation is implemented (the `labelSelector` approach needs further investigation).

Reviewed-on: #136

apps/base/traefik-system/gatewayclass-external.yaml

@@ -4,4 +4,4 @@ kind: GatewayClass
 metadata:
   name: traefik-external
 spec:
-  controllerName: traefik.io/gateway-controller-external
+  controllerName: traefik.io/gateway-controller

apps/base/traefik-system/gatewayclass-internal.yaml

@@ -4,4 +4,4 @@ kind: GatewayClass
 metadata:
   name: traefik-internal
 spec:
-  controllerName: traefik.io/gateway-controller-internal
+  controllerName: traefik.io/gateway-controller