feat(cyberchef)!: NetworkPolicy, on by default

Major, as every chart in this rollout is: networkPolicy.enabled defaults to
true, so the object reaches running releases on the next upgrade.

The simplest policy of the sweep, and the one to read first. CyberChef is a
static web app - nginx serves files, the recipes run in the visitor's browser,
the pod holds no state and calls nothing - so what the policy buys is the two
CEILINGS rather than any source restriction: inbound is capped at 8080, the
single port the pod declares, and outbound at DNS, which is as tight as the
object goes without breaking name resolution.

The 8080 rule carries no source selector by default, and that is deliberate
rather than an oversight: 8080 is the port all three probes address, and the
kubelet probes from the IP of the worker node running the pod, which no chart
can know. Guessing it wrong leaves the pod permanently un-Ready, a symptom that
reads as a broken application. Narrowing it is networkPolicy.probeSources, and
the restricted branch then also carries the ingress controller - measured as
the rke2-traefik DaemonSet in kube-system, which serves this chart's HTTPRoute
as well, since the same Traefik backs the Gateway API here.

Part of #5

cyberchef/values.yaml

@@ -125,3 +125,81 @@ httpRoute:
   # is how a migration from the Ingress runs: the HTTPRoute takes a second
   # hostname while the Ingress keeps ingress.domain.
   hostnames: []
+
+# ---------------------------------------------------------------------------
+# NetworkPolicy (Gitea #5). On by default. The reference implementation with
+# the full reasoning is template-chart; the convention is in README, "Chart
+# style guidelines", and the operator's view on this chart's wiki page.
+# ---------------------------------------------------------------------------
+networkPolicy:
+  # WHAT THIS POLICY ALLOWS: inbound 8080 only - the single port this pod
+  # declares - and outbound nothing but DNS. CyberChef is a static web app
+  # whose recipes run in the browser, so the pod has no reason to open an
+  # outbound connection at all, which makes the egress cap unusually tight.
+  #
+  # WHAT IT DOES NOT DO: the 8080 rule is NOT restricted by source in the
+  # default, because 8080 is the port all three probes address - see
+  # probeSources below. So this policy is a port and egress ceiling, not
+  # pod-level isolation. And it is only a boundary where the CNI enforces
+  # policies; unenforced, it is accepted and filters nothing.
+  enabled: true
+  # Namespaces whose pods may reach this workload, in addition to the release's
+  # own namespace, which is always allowed. Empty means: own namespace only.
+  #
+  # Matched on the "kubernetes.io/metadata.name" label Kubernetes sets on every
+  # namespace itself, so no labelling work is needed on a namespace this chart
+  # does not own - and no typo protection either: a name that does not exist
+  # matches nothing and is silently ineffective. Note the granularity: an entry
+  # opens the port to EVERY pod in that namespace.
+  allowedNamespaces: []
+  # Source CIDRs allowed to reach port 8080, which is the port all three probes address.
+  #
+  # EMPTY MEANS OPEN, NOT BLOCKED. With no entry that rule is rendered WITHOUT a
+  # "from" selector, so the port is reachable from anywhere the CNI routes to -
+  # inside the cluster, since it carries no NodePort.
+  #
+  # That is the deliberate choice between two bad defaults. The kubelet's probes
+  # originate from the IP of the WORKER NODE running the pod, an address this
+  # chart cannot know and must not guess: a CIDR that excludes the real node
+  # blocks every probe, the pod never becomes Ready, the rollout times out, and
+  # the symptom reads as a broken application rather than as a policy.
+  #
+  # Narrow it by listing the worker node IPs (e.g. ["10.0.1.11/32"]) - and mind
+  # the companion trap: once this list is non-empty the rule IS restricted, so
+  # everything else that needs the port has to be in it. The chart adds the own
+  # namespace, the ingressController below and allowedNamespaces to the same rule for exactly that reason.
+  probeSources: []
+  # The ingress controller allowed to reach the routed port once probeSources
+  # restricts it. Rendered only while ingress.enabled or httpRoute.enabled is true, and only in
+  # the restricted branch - with the default (open) rule the controller reaches
+  # the port anyway. The two keys become ONE "from" entry and are therefore an
+  # AND: pods carrying podLabels IN namespace. That is the point of having them
+  # at all - the controller's namespace in allowedNamespaces would open the port
+  # to every pod in kube-system.
+  #
+  # MEASURED ON THIS CLUSTER, NOT ASSUMED (2026-10-14): ingress-nginx is gone,
+  # the only IngressClass is "traefik" and it is the default, and the controller
+  # is the DaemonSet rke2-traefik in kube-system. The same Traefik serves the
+  # Gateway API here, so this one source covers the Ingress and the HTTPRoute
+  # path alike. A policy written against the wrong controller is accepted, looks
+  # strict, and silently blocks all web traffic - and ingress.className says
+  # nothing about it, because a class names an implementation, not the pods the
+  # traffic comes from.
+  ingressController:
+    namespace: kube-system
+    podLabels:
+      app.kubernetes.io/name: rke2-traefik
+  egress:
+    # Additional outbound TCP ports. DNS (UDP and TCP 53) is always allowed and
+    # has no switch - a knob whose only other setting breaks every name lookup
+    # in the pod is a trap, not a feature.
+    #
+    # PORTS, NOT DESTINATIONS, and that is a limit of the object rather than
+    # laziness: a NetworkPolicy matches CIDRs and selectors and never hostnames,
+    # so "only to the database host" cannot be written at all. Each entry
+    # permits its port to ANY destination. What the cap still buys is real: a
+    # compromised pod cannot open arbitrary outbound connections.
+    #
+    # Nothing is needed here for CyberChef itself. Add 443 only if something
+    # is put in front of the pod that has to call out.
+    extraPorts: []