[Epic] specfact backlog

[djm81]

Why

Parent issue for the specfact backlog command. Use this issue to group and track all backlog-related work (dependency analysis, add, daily standup, sprint planning, story complexity, kanban flow, safe PI, risk rollups, definition of done).

What

• Command: specfact backlog (and subcommands: daily, add, refine, analyze-deps, flow, pi-summary, sprint-summary, etc.)
• Purpose: Assign child issues and change proposals to this parent via Relationships (e.g. "tracks" or sub-issues) or project Type grouping.
• OpenSpec: Changes are under openspec/changes/backlog-NN-*. See openspec/CHANGE_ORDER.md for order and blocked-by.

Acceptance Criteria

• All backlog-related issues are linked to this parent (via Relationships or project Type/parent field).
• Implementation order follows CHANGE_ORDER.md (backlog-01 before backlog-02, etc.).