fix: publish under the standard kebab component token + envelope-projection stance

[mbreissi]

The bug

A default run of this adapter published under MtconnectAdapter:

ecv1/demo-thing/MtconnectAdapter/okuma/data/axes-axes/linear-x/lx1actm

while every document in this repository — the messaging reference, the tutorial, the metrics
reference, the how-to guides — says mtconnect-adapter.

Why

libs/rust/src/config/identity.rs resolves the UNS component token as component.token when
configured, otherwise the short form of the component name (the segment after the last .).
This adapter passes the Greengrass component name com.mbreissi.edgecommons.MtconnectAdapter, so
the fallback yields PascalCase. No configuration here set component.token.

The standard is lower-kebab on the wire — the canonical config schema pins
component.token to ^[a-z0-9]+(?:-[a-z0-9]+)*$ and describes it as "First-party EdgeCommons
components use lower-kebab tokens (for example, opcua-adapter) while their Greengrass component
names use the com.mbreissi.edgecommons.<Name> pattern." The reference adapters follow it:
opcua-adapter and modbus-adapter set component.token in every configuration they ship.

The fix

Same mechanism as the siblings — component.token, no code change — applied to every configuration
surface this component ships: test-configs/config.json, test-configs/mtconnect.json,
k8s/configmap.yaml, and recipe.yaml (the Greengrass default configuration).

Documentation follows the now-true token: the README quick start (its config, its captured topics,
and its envelope example), the four sample configurations, and the configuration and messaging
references — which now also record where the token comes from, and that the Greengrass component
name never appears on the wire.

Envelope JSON-projection stance

The messaging reference's envelope section now opens with the canonical stance: the envelope is
documented in its JSON projection — the canonical field names and shapes; the MQTT/IPC wire encoding
is the protobuf envelope (proto/edgecommons/v1), which round-trips this projection exactly.

Validation

cargo test — 362 tests, all green.

Live run against EMQX on localhost:1883 (--platform HOST --transport MQTT, -c FILE ./test-configs/config.json -t demo-thing), subscriber on ecv1/#:

ecv1/demo-thing/mtconnect-adapter/cfg
ecv1/demo-thing/mtconnect-adapter/state
ecv1/demo-thing/mtconnect-adapter/device-1/data/temperature-1
ecv1/demo-thing/mtconnect-adapter/device-1/data/pressure-1
ecv1/demo-thing/mtconnect-adapter/device-1/evt/info/device-connected
ecv1/demo-thing/mtconnect-adapter/device-1/evt/critical/device-unreachable

The protobuf payloads carry the matching identity: path factory-1/demo-thing, component
mtconnect-adapter, instance device-1.