fix(ci): add RBAC for Argo sensor workflow submission

argo-workflow SA needs workflows/create and workflowtemplates/get
permissions to submit CI pipelines from sensor triggers.

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

infra/k8s/argo/events/rbac.yaml

@@ -0,0 +1,29 @@
+apiVersion: rbac.authorization.k8s.io/v1
+kind: Role
+metadata:
+  name: argo-sensor-submit
+  namespace: foxhunt
+rules:
+  - apiGroups: ["argoproj.io"]
+    resources: ["workflows"]
+    verbs: ["create", "get", "list", "watch"]
+  - apiGroups: ["argoproj.io"]
+    resources: ["workflowtemplates"]
+    verbs: ["get", "list"]
+  - apiGroups: ["argoproj.io"]
+    resources: ["workflowtaskresults"]
+    verbs: ["create", "patch"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: argo-sensor-submit
+  namespace: foxhunt
+subjects:
+  - kind: ServiceAccount
+    name: argo-workflow
+    namespace: foxhunt
+roleRef:
+  kind: Role
+  name: argo-sensor-submit
+  apiGroup: rbac.authorization.k8s.io