Add Space leader command rail

src/main.zig

@@ -1,6 +1,7 @@
 const std = @import("std");
 const input = @import("input.zig");
 const layout = @import("layout.zig");
+const leader = @import("leader.zig");
 const protocol = @import("protocol.zig");
 const replay = @import("replay.zig");
 const session = @import("session.zig");
@@ -120,6 +121,7 @@ fn collectRemainingArgs(allocator: std.mem.Allocator, args: *std.process.Args.It
 test {
     _ = input;
     _ = layout;
+    _ = leader;
     _ = protocol;
     _ = replay;
     _ = session;