api: add /random/tag

lib/PoorBooru/API/V0.pm

@@ -24,6 +24,8 @@ sub startup ($self)
 
 	$r->get("/tags")->to("tags#list");
 	$r->get("/tag/:tag_id_or_name")->to("tags#show");
+
+	$r->get("/random/tag")->to("random#tag");
 }
 
 1;

lib/PoorBooru/API/V0/Controller/Random.pm

@@ -0,0 +1,21 @@
+package PoorBooru::API::V0::Controller::Random;
+use v5.36;
+use strict;
+use warnings;
+
+use Mojo::Base "Mojolicious::Controller";
+
+sub tag ($self)
+{
+	my $tag = $self->schema->resultset("Tag")
+	    ->search({}, { order_by => \"random()", limit => 1 })->single;
+
+	return $self->render(
+		json => {error => "Tag not found"},
+		status => 404,
+	) if !defined($tag);
+
+	return $self->redirect_to("/tag/" . $tag->name);
+}
+
+1;