feat(cli): report groups by task, not only filters to one #720

Outcome

A person can ask where a period's effort went between tasks, in one command, the same way they can already ask it between steps, models, tools and projects.

Scope

aidd telemetry report today accepts --task <yyyy_mm>/<name> as a filter: it restricts a report to one task. There is no way to group by task. The six axes are total | day | step | model | tool | project — task is not among them, and no by_task array exists in the JSON envelope.

So the question "which of my tasks cost the most this month" can only be answered by knowing every task name up front and running the command once per name, then adding up the results by hand. Every other dimension the layer records answers it in one call.

• Includes: a by_task breakdown in the report envelope, beside by_step, by_model, by_tool and by_project.
• Includes: task as an --axis value, so the artefact table can be pasted like the other five.
• Includes: sessions that wrote into no task as their own row, never folded into another and never dropped — the same rule unattributed already follows on the step axis.
• Excludes: any change to how a task is attributed. This groups what the journal already records; it does not widen it.
• Excludes: the link from a task to its backlog item, which is feat(framework): a task identity file linking delivery to its backlog item #649.

Why it is not covered elsewhere

• feat(framework): a task identity file linking delivery to its backlog item #649 gives a task an identity file pointing at its backlog item. That is the link outward; this is the breakdown inward, and neither implies the other.
• feat(framework): a unit of AIDD work carries its cost #631 makes a unit of AIDD work carry its cost — one unit, its figure. This is the comparison across units.
• feat(framework): report per person, team and epic #656 reports per person, team and epic. Task is a different grain and is named nowhere in it.

Done When

• aidd telemetry report prints a by task section, ordered like the other axes.
• --axis task produces a table with the same columns as the other five artefacts.
• report --json carries by_task, and its rows reconcile to totals exactly, as every other breakdown already does.
• Work belonging to no task appears as its own row with an explicit label, and the total says how much of the period it accounts for.

Relations