Add --(enable|disable)-natsort options

ncdu.pod

@@ -252,6 +252,10 @@ The column can be suffixed with I<-asc> or I<-desc> to set the order to
 ascending or descending, respectively. e.g. C<--sort=name-desc> will sort by
 name in descending order.
 
+=item B<--enable-natsort>, B<--disable-natsort>
+
+Enable (default) or disable natural sort when sorting by file name.
+
 =item B<--group-directories-first>, B<--no-group-directories-first>
 
 Sort (or not) directories before files.

src/browser.zig

@@ -103,10 +103,10 @@ fn sortLt(_: void, ap: ?*model.Entry, bp: ?*model.Entry) bool {
         },
     }
 
-    const an = a.name();
-    const bn = b.name();
-    return if (main.config.sort_order == .asc) util.strnatcmp(an, bn) == .lt
-           else util.strnatcmp(bn, an) == .lt;
+    const an = (if (main.config.sort_order == .asc) a else b).name();
+    const bn = (if (main.config.sort_order == .asc) b else a).name();
+    return if (main.config.sort_natural) util.strnatcmp(an, bn) == .lt
+           else std.mem.lessThan(u8, an, bn);
 }
 
 // Should be called when:

src/main.zig

@@ -66,6 +66,7 @@ pub const config = struct {
     pub var sort_col: SortCol = .blocks;
     pub var sort_order: SortOrder = .desc;
     pub var sort_dirsfirst: bool = false;
+    pub var sort_natural: bool = true;
 
     pub var imported: bool = false;
     pub var can_delete: ?bool = null;
@@ -183,6 +184,8 @@ fn argConfig(args: *Args, opt: Args.Option) bool {
     else if (opt.is("--hide-percent")) config.show_percent = false
     else if (opt.is("--group-directories-first")) config.sort_dirsfirst = true
     else if (opt.is("--no-group-directories-first")) config.sort_dirsfirst = false
+    else if (opt.is("--enable-natsort")) config.sort_natural = true
+    else if (opt.is("--disable-natsort")) config.sort_natural = false
     else if (opt.is("--graph-style")) {
         const val = args.arg();
         if (std.mem.eql(u8, val, "hash")) config.graph_style = .hash