Finish the API endpoint for cover upload

src/handlers/static_handler.cr

@@ -0,0 +1,32 @@
+require "baked_file_system"
+require "kemal"
+require "../util"
+
+class FS
+  extend BakedFileSystem
+  {% if flag?(:release) %}
+    {% if read_file? "#{__DIR__}/../../dist/favicon.ico" %}
+      {% puts "baking ../../dist" %}
+      bake_folder "../../dist"
+    {% else %}
+      {% puts "baking ../../public" %}
+      bake_folder "../../public"
+    {% end %}
+  {% end %}
+end
+
+class StaticHandler < Kemal::Handler
+  @dirs = ["/css", "/js", "/img", "/favicon.ico"]
+
+  def call(env)
+    if request_path_startswith env, @dirs
+      file = FS.get? env.request.path
+      return call_next env if file.nil?
+
+      slice = Bytes.new file.size
+      file.read slice
+      return send_file env, slice, file.mime_type
+    end
+    call_next env
+  end
+end