Answer what the records keep, collect on a person's word, and name a machine's images (hq ADR 0251)

The store's tools and a machine's image pruning decide from the records, so
the controller says them: artifacts (every recorded artifact, kept and why,
eligible, collected on request), collect (the after-build sweep on demand,
a dry run unless confirmed with a why, recorded as a hand act) and images
(what a machine's declaration names, now and as last sent). The sweep is one
implementation with two sets of bounds.

internal/catalogue/verbs.go

@@ -435,6 +435,34 @@ var ControllerVerbs = []Verb{
 			"behind": "\"true\", instead of a repository: build every module the mesh holds whose source has moved " +
 				"past the commit it was built from, bases asked first",
 		}, nil, "behind")},
+	// What the records say the registries may keep, asked on demand (novox/hq ADR 0251, to-be 51).
+	{Name: "artifacts", Description: "Every artifact the mesh recorded making that lives in its artifact store, " +
+		"each with its repository, digest, kind (image or archive) and state: kept — and why: a definition names " +
+		"it, or one of the five most recent builds of a module the mesh holds — or eligible: made, kept for no " +
+		"reason, not yet let go. Collected ones are counted, and listed only with collected. Reads only " +
+		"(novox/hq ADR 0251).",
+		Input: schema(map[string]string{
+			"repository": "only this repository's references, as <module>/<artifact> (the counts stay whole)",
+			"collected":  "\"true\": list the collected references too (they only grow; counted always)",
+		}, nil, "collected")},
+	{Name: "collect", Description: "The artifact store's sweep, now: what the mesh made and keeps for no reason " +
+		"is let go of. Without confirm a dry run — every kept archive asked about with HEADs, what would be let go " +
+		"listed, nothing held or deleted. With confirm and why: every kept archive held first, then each eligible " +
+		"artifact let go of, oldest first, and recorded collected — a hand act, recorded with its why. Bounded by " +
+		"most (500 by default, at most 5000) and 45 seconds; what is left is said. Bytes are reclaimed by the " +
+		"store's nightly collector. Never touches a digest the mesh did not record (novox/hq ADR 0189, ADR 0251).",
+		Input: schema(map[string]string{
+			"confirm": "\"true\": let go of what is eligible (needs why); without it nothing is done",
+			"why":     "with confirm: why — required, and recorded in the hand-act log",
+			"most":    "let go of at most this many (500 by default, at most 5000)",
+		}, nil, "confirm")},
+	{Name: "images", Description: "Every container image one machine's declaration names — the declaration the " +
+		"mesh would send it now and the one it was last sent — each with the resources naming it: what the " +
+		"machine keeps when it prunes its images. sent_known is false when the last one sent is not kept with " +
+		"its images. Reads only (novox/hq ADR 0251).",
+		Input: schema(map[string]string{
+			"node": "the machine's name",
+		}, []string{"node"})},
 }
 
 // schema is a JSON schema for an object of string properties, which is every argument the verbs