Fix /home/kamal-proxy/.config/kamal-proxy ownership

1. Update to kamal-proxy 0.4.0 which creates and chowns
/home/kamal-proxy/.config/kamal-proxy to kamal-proxy
2. Use a docker volume rather than mapping in a directory, so docker
keeps it owned by the correct user

lib/kamal/cli/proxy.rb

@@ -167,7 +167,6 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
         stop
         remove_container
         remove_image
-        remove_host_directory
       end
     end
   end
@@ -192,16 +191,6 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
     end
   end
 
-  desc "remove_host_directory", "Remove proxy directory from servers", hide: true
-  def remove_host_directory
-    with_lock do
-      on(KAMAL.proxy_hosts) do
-        execute *KAMAL.auditor.record("Removed #{KAMAL.config.proxy_directory}"), verbosity: :debug
-        execute *KAMAL.proxy.remove_host_directory, raise_on_non_zero_exit: false
-      end
-    end
-  end
-
   private
     def removal_allowed?(force)
       on(KAMAL.proxy_hosts) do |host|

lib/kamal/commands/proxy.rb

@@ -8,8 +8,7 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
       "--detach",
       "--restart", "unless-stopped",
       *config.proxy_publish_args,
-      "--volume", "/var/run/docker.sock:/var/run/docker.sock",
-      *config.proxy_config_volume.docker_args,
+      "--volume", "kamal-proxy-config:/home/kamal-proxy/.config/kamal-proxy",
       *config.logging_args,
       config.proxy_image
   end
@@ -57,10 +56,6 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
     docker :image, :prune, "--all", "--force", "--filter", "label=org.opencontainers.image.title=kamal-proxy"
   end
 
-  def remove_host_directory
-    remove_directory config.proxy_directory
-  end
-
   def cleanup_traefik
     chain \
       docker(:container, :stop, "traefik"),

lib/kamal/configuration.rb

@@ -14,7 +14,7 @@ class Kamal::Configuration
 
   include Validation
 
-  PROXY_MINIMUM_VERSION = "v0.3.0"
+  PROXY_MINIMUM_VERSION = "v0.4.0"
   PROXY_HTTP_PORT = 80
   PROXY_HTTPS_PORT = 443
 
@@ -216,10 +216,6 @@ class Kamal::Configuration
     File.join apps_directory, [ service, destination ].compact.join("-")
   end
 
-  def proxy_directory
-    File.join run_directory, "proxy"
-  end
-
   def env_directory
     File.join app_directory, "env"
   end
@@ -262,12 +258,6 @@ class Kamal::Configuration
     "kamal-proxy"
   end
 
-  def proxy_config_volume
-    Kamal::Configuration::Volume.new \
-      host_path: File.join(proxy_directory, "config"),
-      container_path: "/home/kamal-proxy/.config/kamal-proxy"
-  end
-
 
   def to_h
     {