Add run_command_file to proxy boot

lib/kamal/cli/proxy.rb

@@ -78,7 +78,7 @@ class Kamal::Cli::Proxy < Kamal::Cli::Base
         end
 
         if run_command
-          upload! StringIO.new(run_command), KAMAL.config.proxy_run_command_file
+          upload! StringIO.new(run_command), proxy_boot_config.run_command_file
         else
           execute *KAMAL.proxy.reset_run_command, raise_on_non_zero_exit: false
         end

lib/kamal/commands/proxy.rb

@@ -86,7 +86,7 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
   end
 
   def read_run_command
-    read_file(config.proxy_run_command_file)
+    read_file(config.proxy_boot.run_command_file)
   end
 
   def reset_boot_options
@@ -102,7 +102,7 @@ class Kamal::Commands::Proxy < Kamal::Commands::Base
   end
 
   def reset_run_command
-    remove_file config.proxy_run_command_file
+    remove_file config.proxy_boot.run_command_file
   end
 
   private

lib/kamal/configuration/proxy/boot.rb

@@ -66,6 +66,10 @@ class Kamal::Configuration::Proxy::Boot
     File.join host_directory, "image_version"
   end
 
+  def run_command_file
+    File.join host_directory, "run_command"
+  end
+
   def apps_directory
     File.join host_directory, "apps-config"
   end