feat(framework): work is attached to what it delivers #648

A measured cost is attached to the work it belongs to, and readable where the developer already looks.

Context and Value

The first milestone answers "what did this task cost". It answers it about a folder, in isolation. Nothing says which ticket that folder serves, which story it delivers, or which epic it rolls up to — and nothing shows any of it on the screen a developer already opens.

Two gaps make that so, both verified in this repository:

• No artefact links a delivery folder to its backlog item. The relation model exists and is well formed (plugins/aidd-pm/skills/*/references/relations.md), but no skill writes the edge from aidd_docs/tasks/<month>/<folder>/ upward.
• Delivery artefacts are invisible to the board. plan.md and phase-N.md carry status but no type; spec.md and review.md carry no frontmatter at all. The kanban's own product brief already records the consequence: its --type filter returns nothing on this framework's own documents.

Boundaries

• Includes: a task identity file linking a delivery folder to its backlog item, whatever support that backlog lives on.
• Includes: the missing frontmatter on delivery artefacts.
• Includes: the board reading execution — sessions, steps, durations — beside the status it already reads.
• Excludes: mirroring a backlog across supports. persistence.md forbids it, and this milestone must not create the drift it forbids.
• Excludes: cost aggregation across people or repositories, and anything hosted.
• Excludes: the four remaining tools.

Success Evidence

Opening the board on a real project shows a feature, the steps that ran, how long each took, and the ticket it came from — without opening a folder. The failure signal is two sources of truth for the same field, which is what the design rules exist to prevent.

Design: aidd_docs/specs/2026_08/2026_08_13-work-tracking-linkage.md