Record a drill through its own verb, so S15 never counts a deliberate test as a repair

Two ADR 0240 drills recorded with hand-act record --cause drill raised
mesh.hand-acts.drill.healer-wanted. hand-act drill (seat verb drill) records
them as a person's decision; hand-act record now refuses the cause, so the
two recorded before it clear on the next tick and a repair cannot pass for a
drill by the word it gives.

cmd/mesh-controller/seatverbs.go

@@ -456,6 +456,15 @@ func (a *verbArguments) commandLine() ([]string, error) {
 			argv = append(argv, "--condition", c)
 		}
 		return argv, nil
+	case "drill":
+		if err := need("what", "why"); err != nil {
+			return nil, err
+		}
+		argv := []string{"hand-act", "drill", str("what"), "--why", str("why")}
+		if c := str("condition"); c != "" {
+			argv = append(argv, "--condition", c)
+		}
+		return argv, nil
 	case "hand-acts":
 		argv := []string{"hand-acts", "--json"}
 		if d := str("days"); d != "" {
@@ -723,6 +732,8 @@ func repairingCommand(argv []string) string {
 		return "plans " + argv[1]
 	case argv[0] == "broker" && len(argv) > 1 && argv[1] == "consumer-reset":
 		return "broker consumer-reset"
+	case argv[0] == "hand-act" && len(argv) > 1 && argv[1] == "drill":
+		return "hand-act drill"
 	case argv[0] == "hand-act":
 		return "hand-act record"
 	case argv[0] == "conditions" && len(argv) > 1 && argv[1] == "silence":