Breaking change in Consul CLI when registering a service with a schema in the address; Discrepancy between CLI and HTTP API behavior

#### Overview of the Issue

Reporting a *breaking* change on `v1.21` introduced by this commit https://github.com/hashicorp/consul/commit/6f87b06f4c6cb47b6f20c11f790eb7fd7c3784cc.

In our application, we are registering services with their full addresses. This includes the scheme, the hostname, and sometimes a path. This fully qualified URL is, in fact, a K8s ingress URL.

ℹ️ It is to be noted that while the CLI will prevent the registration of a service with an address that contains a scheme. The API HTTP handler will not behave the same way and happily accept an incoming request with a payload `{"Name":"foo","Address":"https://foo.example.org"}`. See more in the repro steps section.

> I acknowledge that the undocumented breaking changes is most likely caused by an improper usage, or value, of the address field. But I hope that if this issue get categorized as `Not a bug`, I can receive help or guide line to solve my issue preventing me to upgrade.

---

#### Reproduction Steps

1. Create a cluster in version `v1.20` (any patch version; as of the day of writing, it is `v1.20.6`.)
> I personnally simply create a single container using `docker run hashicorp/consul:x.y.z`.
3. Run the CLI as `consul services register -name foo -address https://foo.example.org`.
4. Observe the output:
```
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
6a3a40182027 hashicorp/consul:1.20 "docker-entrypoint.s…" 6 seconds ago Up 5 seconds 8300-8302/tcp, 8500/tcp, 8301-8302/udp, 8600/tcp, 8600/udp inspiring_mccarthy
$ docker exec 6a3a40182027 consul services register -name foo -address https://foo.example.org
Registered service: foo
```

Then
1. Create a cluster in version `v1.21.3` or above, `v1.22.0` (or above), or `v1.22.0` (or above).
> As of the day of writing, latest patch version are respectively `v1.21.7` and `v1.22.6`.
2. Re-run the same CLI command and observe the output behave differently:

```
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
42fbeaa21eca hashicorp/consul:1.22.6 "docker-entrypoint.s…" 26 seconds ago Up 25 seconds 8300-8302/tcp, 8500/tcp, 8301-8302/udp, 8600/tcp, 8600/udp jolly_darwin
$ docker exec 42fbeaa21eca consul services register -name foo -address https://foo.example.org
Invalid Service address when using CLI flags. Use -port flag instead: address should not contain port
```
3. Run a `curl` command to register the service with the payload `{"Name":"foo","Address":"https://foo.example.org"}` and see the happily registered service, which **is a different behavior** from the CLI.

```
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
2b48a05b8668 hashicorp/consul:1.22 "docker-entrypoint.s…" 3 minutes ago Up 3 minutes 8300-8302/tcp, 8301-8302/udp, 8600/tcp, 8600/udp, 0.0.0.0:8500->8500/tcp, [::]:8500->8500/tcp consul
$ docker exec 2b48a05b8668 curl -X PUT http://localhost:8500/v1/agent/service/register -H "Content-Type: application/json" -d '{"Name":"foo","Address":"https://foo.example.org"}'
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 50 0 0 100 50 0 28264 --:--:-- --:--:-- --:--:-- 50000
$ docker exec 2b48a05b8668 curl http://localhost:8500/v1/catalog/service/foo
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 1100 100 1100 0 0 1424k 0 --:--:-- --:--:-- --:--:-- 1074k
[
{
"ID": "e057088c-6117-aa9e-ee26-c016759ec181",
"Node": "2b48a05b8668",
"Address": "127.0.0.1",
"Datacenter": "dc1",
"TaggedAddresses": {
"lan": "127.0.0.1",
"lan_ipv4": "127.0.0.1",
"wan": "127.0.0.1",
"wan_ipv4": "127.0.0.1"
},
"NodeMeta": {
"consul-network-segment": "",
"consul-version": "1.22.6"
},
"ServiceKind": "",
"ServiceID": "foo",
"ServiceName": "foo",
"ServiceTags": [],
"ServiceAddress": "https://foo.example.org",
"ServiceWeights": {
"Passing": 1,
"Warning": 1
},
"ServiceMeta": {},
"ServicePort": 0,
"ServicePorts": null,
"ServiceSocketPath": "",
"ServiceEnableTagOverride": false,
"ServiceProxy": {
"Mode": "",
"MeshGateway": {},
"Expose": {}
},
"ServiceConnect": {},
"ServiceLocality": null,
"CreateIndex": 18,
"ModifyIndex": 18
}
]%
```

### Consul info for both Client and Server

Client info

```
agent:
check_monitors = 0
check_ttls = 0
checks = 0
services = 0
build:
prerelease =
revision = 97566680
version = 1.22.6
version_metadata =
consul:
acl = disabled
bootstrap = false
known_datacenters = 1
leader = true
leader_addr = 127.0.0.1:8300
server = true
raft:
applied_index = 19
commit_index = 19
fsm_pending = 0
last_contact = 0
last_log_index = 19
last_log_term = 2
last_snapshot_index = 0
last_snapshot_term = 0
latest_configuration = [{Suffrage:Voter ID:de5acb44-eede-0f78-956d-b77023788db7 Address:127.0.0.1:8300}]
latest_configuration_index = 0
num_peers = 0
protocol_version = 3
protocol_version_max = 3
protocol_version_min = 0
snapshot_version_max = 1
snapshot_version_min = 0
state = Leader
term = 2
runtime:
arch = arm64
cpu_count = 10
goroutines = 196
max_procs = 10
os = linux
version = go1.25.8
serf_lan:
coordinate_resets = 0
encrypted = false
event_queue = 1
event_time = 2
failed = 0
health_score = 0
intent_queue = 0
left = 0
member_time = 1
members = 1
query_queue = 0
query_time = 1
serf_wan:
coordinate_resets = 0
encrypted = false
event_queue = 0
event_time = 1
failed = 0
health_score = 0
intent_queue = 0
left = 0
member_time = 1
members = 1
query_queue = 0
query_time = 1
```

```
default from the CLI embeded in the docker image `hashicorp/consul:1.22`
```

Server info

```
default from `docker pull hashicorp/consul:1.22`
```

```
default from `docker pull hashicorp/consul:1.22`
```

### Operating system and Environment details

MacBook Pro M2 - MacOS 26.2

### Log Fragments

No log. Just an error message. See above.

Start by tracing the `consul services register` CLI entry point and the `/v1/agent/service/register` HTTP handler, comparing how each validates a service address. Reproduce the behavior on the cited Consul versions and define done as consistent handling of schemed addresses between the CLI and API, with regression coverage for the reported payload and command.

Written by the indexing model from the issue text.