feat(infra): CONNECTS_TO -- a service address in a container's environment

A workload's environment names the services it talks to
(PRODUCT_CATALOG_SERVICE_ADDR: productcatalogservice:3550, a URL, a
<svc>.<ns>.svc name); the graph had no edge for it, so the service topology
of an application was invisible.

A Kubernetes workload or a compose service now CONNECTS_TO the Service its
containers' environment addresses, with {via: env, key, container} -- never
the value:
- the address: the host of a URL or of host:port, a <svc>.<ns>.svc name in
  the value, or the whole value when the key names an address (*_ADDR,
  *_ADDRESS, *_HOST, *_URL, *_ENDPOINT, *_URI) and it is a bare DNS name; a
  templated value, localhost or an IP addresses nothing, and only service DNS
  forms count (svc, svc.ns, svc.ns.svc...), never another domain's host
  (cbm_env_address, shared by both sides);
- Kubernetes: a reference resolved like every other one -- a Service of the
  same bundle, in the named namespace or the object's own;
- compose: a service of the same file; a variable without a value takes the
  project's .env, whose values compose expands against the lines before them
  (CART_ADDR=cart:${CART_PORT}) -- the dotenv reader does that now too.

Consumers: trace_path's topology mode, the CLI's edge list and the README
(which also gains DEPLOYS and the env join of the previous commit).

Measured on 17 infrastructure repositories: 129 edges, every one correct by
hand; an independent reading of the values finds 133 pairs repo-wide, the 5
without an edge belong to another bundle or namespace.

Signed-off-by: Martin Vogel <martin.vogel.tech@gmail.com>

src/cli/cli.c

@@ -1568,7 +1568,9 @@ static const char skill_content[] =
     "HANDLES, IMPLEMENTS, OVERRIDE, USAGE, CALL_REFERENCE, CONFIGURES, REFERENCES_FILE,\n"
     "MENTIONS (doc comment -> referenced code), FILE_CHANGES_WITH, SIMILAR_TO,\n"
     "SEMANTICALLY_RELATED, CONTAINS_FILE, CONTAINS_FOLDER,\n"
-    "INFRA_MAPS (K8s Service -> selected workloads), DEPENDS_ON (chart / manifest -> dependency)\n"
+    "INFRA_MAPS (K8s Service -> selected workloads), DEPENDS_ON (chart / manifest -> dependency),\n"
+    "DEPLOYS (what puts manifests / charts on a cluster -> what it puts there),\n"
+    "CONNECTS_TO (workload / compose service -> the Service its environment addresses)\n"
     "\n"
     "## Cypher Examples (for query_graph)\n"
     "```\n"