fix(cli): assign-schedule-type dispatch at top level

`assign-schedule-type` is registered in CommandSurface() as a Group, so
the default branch of main()'s switch picks it up via findGroup() and
hands it to handleGroup. handleGroup then treats args[0] (the agent-id)
as a subcommand name, fails findSubCommand, and errors:

    unknown assign-schedule-type subcommand: <agent-id>

The group has no subcommands — it's a leaf — so the call never reaches
handleAssignScheduleType. Add an explicit top-level case before the
default branch so the leaf bypasses the group dispatcher.

Pre-fix repro:
    $ AGENT_ID=ard hf assign-schedule-type analyst1 standard
    unknown assign-schedule-type subcommand: analyst1

Post-fix:
    $ AGENT_ID=ard CLAW_IDENTIFIER=server-t2 hf assign-schedule-type analyst1 standard
    Assigned schedule type 'standard' to agent 'analyst1'

Surfaced during recruitment workflow Step 5 on prod (sherlock/agent-resource-director).

cmd/hf/main.go

@@ -68,6 +68,11 @@ func main() {
 		default:
 			output.Errorf("unknown agent subcommand: %s", args[1])
 		}
+	case "assign-schedule-type":
+		// Leaf command (no subcommands) — args are <agent-id> <type-name>.
+		// Must dispatch at top level because handleGroup treats args[0] as
+		// a subcommand name and would error "unknown ... subcommand: <agent-id>".
+		handleAssignScheduleType(args[1:])
 	default:
 		if group, ok := findGroup(args[0]); ok {
 			handleGroup(group, args[1:])