Bug: Incorrect identity used in MQTT LWT payload

[JeffMboya]

What were you trying to achieve?

Ensure each component publishes a unique offline LWT identity matching its actual runtime instance

What are the expected results?

LWT payload should include the real instance identity, not the shared SuperMQ credential

What are the received results?

LWT uses username instead of the actual MQTT ClientID or instance ID, creating ambiguous offline events

Steps To Reproduce

Start multiple services sharing one ClientID; inspect their LWT payloads during disconnect

In what environment did you encounter the issue?

Docker Compose with TLS-enabled MQTT using Paho clients in Go services

Additional information you deem important

Ambiguity arises from mixing ClientID, InstanceID, and username; LWT field name proplet_id mismatches its actual value

[rodneyosodo]

The fix should ensure each component's Last Will and Testament (LWT) payload uses its unique MQTT ClientID instead of the shared username credential. This resolves ambiguous offline events by making each instance's disconnection identifiable. Additionally, the C implementation's LWT code should be uncommented, and all three language implementations must consistently use ClientID in the proplet_id field to align the field name with its actual meaning.