Counts status transitions within the half-open window [from, to), one count per status, keyed off each status's dedicated transition timestamp (failed → failed_at, pending → created_at, etc.).

This is a flow metric, not a snapshot: a single instruction that transitioned through several statuses inside the window contributes +1 to each of those counts, so the per-status counts do not sum to a row total. This answers questions like "how many instructions failed in the last 24 hours".

Hidden instructions are included only when the requester holds instructions:read_hidden.

Permission: instructions:read (plus instructions:read_hidden to include hidden instructions in the counts).