unifi: Deploy Unifi controller

The Unifi controller consists of three containerized processes:

* Unifi Network itself
* unifi_exporter for monitoring and metrics via Prometheus
* Caddy for HTTPS

_unifi_exporter_ is really the only component with any configuration.
Unfortunately, it mixes secret and non-secret data in a single YAML
file, which makes it impossible to use `yaml.Marshal` to render the
configuration directly from the CUE source.

env/prod/unifi.cue

@@ -0,0 +1,29 @@
+package prod
+
+unifi: caddy: {
+	server_name: "unifi.pyrocufflink.blue"
+	acme: email: "unifi@pyrocufflink.blue"
+}
+
+unifi: exporter: {
+	listen: {
+		address:     ":9130"
+		metricspath: "/metrics"
+	}
+	unifi: {
+		address:  "https://localhost:8443/"
+		insecure: true
+		password: """
+			-----BEGIN AGE ENCRYPTED FILE-----
+			YWdlLWVuY3J5cHRpb24ub3JnL3YxCi0+IFgyNTUxOSBvRVBncFB6YnJsYmlQSnJN
+			YXVqclJVTGV4eTRkd3JWbFhZOXN4WWJYc1NVCnlXdElESWJNdVcxRnZodnVUTlF5
+			d2ovRjNNeE9jV25IOW01MERIM1ZKZnMKLS0tIEFneVBWdHVobzZBTlBvZjZaMHJp
+			T3A4WTRYaDd1RFduVVBnQ3hXSkE0WmcKEFBdNfdUTZSo7ebqcIcl9qckp/zc0Mf6
+			LV9pZz8v3n9NO9fnF/vzXJrGyaJlzv3H
+			-----END AGE ENCRYPTED FILE-----
+			"""
+		site:     "Pyrocufflink"
+		timeout:  "5s"
+		username: "prometheus"
+	}
+}