issue 974: the checks are queued by pull request on two work-queue streams, taken after a delivery build, dropped when judged, stopped when their key moves; the reordering and the forge-asking end are gone

internal/link/build.go

@@ -144,6 +144,12 @@ type CheckRequest struct {
 	Repo   string `json:"repo"`
 	Number int    `json:"number,omitempty"`
 	Base   string `json:"base,omitempty"`
+	// Trunk is the base branch's head the check is asked against, as the forge announced it with the head (novox/hq ADR
+	// 0406 §4): with the head, what the pull request's key says the current check is for, and what a waiting request
+	// is dropped by and a running check stopped by when the key moves.
+	Trunk string `json:"trunk,omitempty"`
+	// Ready says the pull request is marked ready (ADR 0406 §3): its check is queued before every other check.
+	Ready bool `json:"ready,omitempty"`
 	// Paths are the files the pull request changes, for the width of its rebuild.
 	Paths []string `json:"paths,omitempty"`
 	// Beside are the repositories the check reads next to this one, each cloned at the ref given — the