terminal: use LibEnum for the command keys

src/lib/enum.zig

@@ -35,7 +35,8 @@ pub fn Enum(
         fields_i += 1;
     }
 
-    return @Type(.{ .@"enum" = .{
+    // Assigned to var so that the type name is nicer in stack traces.
+    const Result = @Type(.{ .@"enum" = .{
         .tag_type = switch (target) {
             .c => c_int,
             .zig => std.math.IntFittingRange(0, fields_i - 1),
@@ -44,6 +45,7 @@ pub fn Enum(
         .decls = &.{},
         .is_exhaustive = true,
     } });
+    return Result;
 }
 
 pub const Target = union(enum) {