Overview
========

Role in the Commands Architecture
---------------------------------

Within the CSP.LMC commands architecture, a client-issued
**Long Running Command (LRC)** is represented by a ``MainTask`` and
decomposed into a task tree composed of ``Task`` and ``LeafTask``
instances.

These tasks may be executed across multiple CSP subsystems and may
follow parallel or sequential execution patterns depending on the
command semantics.

The Task Tracker operates as an **observer and aggregator** within this
architecture, alongside the following components:

- **MainTask Composer**, which constructs the task tree and defines
  execution structure and dependencies;
- **MainTask Executor**, which drives the execution of tasks and leaf
  tasks.

While the Composer determines *what* is executed and the Executor
controls *when* execution occurs, the Task Tracker is responsible for
*tracking how execution progresses and how it completes*, independently
of execution control.

Core Responsibilities
---------------------

The Task Tracker provides a centralized view of LRC execution by:

- collecting execution updates from tasks and subtasks;
- tracking the lifecycle of a command from acceptance to termination;
- aggregating task statuses and result codes into a single outcome;
- computing and publishing overall command progress;
- emitting exactly one authoritative completion notification;
- enriching the completion outcome with execution context, such as:
  
  - failed devices,
  - aggregated health state,
  - normalized failure causes.

By separating execution control from execution observation, the Task
Tracker ensures consistent, deterministic reporting of command outcomes,
even in the presence of partial failures or subsystem-specific error
conditions.