Run pre-connect hooks before ssh commands

We hook into the SSHKit `on` method to run the pre-connect hook before
the first SSH command. This doesn't work for interactive exec commands
where ssh is called directly.

Fixes: https://github.com/basecamp/kamal/issues/1157

lib/kamal/cli/accessory.rb

@@ -141,6 +141,8 @@ class Kamal::Cli::Accessory < Kamal::Cli::Base
   option :interactive, aliases: "-i", type: :boolean, default: false, desc: "Execute command over ssh for an interactive shell (use for console/bash)"
   option :reuse, type: :boolean, default: false, desc: "Reuse currently running container instead of starting a new one"
   def exec(name, *cmd)
+    pre_connect_if_required
+
     cmd = Kamal::Utils.join_commands(cmd)
     with_accessory(name) do |accessory, hosts|
       case

lib/kamal/cli/app.rb

@@ -106,6 +106,8 @@ class Kamal::Cli::App < Kamal::Cli::Base
   option :env, aliases: "-e", type: :hash, desc: "Set environment variables for the command"
   option :detach, type: :boolean, default: false, desc: "Execute command in a detached container"
   def exec(*cmd)
+    pre_connect_if_required
+
     if (incompatible_options = [ :interactive, :reuse ].select { |key| options[:detach] && options[key] }.presence)
       raise ArgumentError, "Detach is not compatible with #{incompatible_options.join(" or ")}"
     end

lib/kamal/cli/base.rb

@@ -147,12 +147,16 @@ module Kamal::Cli
       end
 
       def on(*args, &block)
+        pre_connect_if_required
+
+        super
+      end
+
+      def pre_connect_if_required
         if !KAMAL.connected?
           run_hook "pre-connect"
           KAMAL.connected = true
         end
-
-        super
       end
 
       def command

lib/kamal/cli/server.rb

@@ -2,6 +2,8 @@ class Kamal::Cli::Server < Kamal::Cli::Base
   desc "exec", "Run a custom command on the server (use --help to show options)"
   option :interactive, type: :boolean, aliases: "-i", default: false, desc: "Run the command interactively (use for console/bash)"
   def exec(*cmd)
+    pre_connect_if_required
+
     cmd = Kamal::Utils.join_commands(cmd)
     hosts = KAMAL.hosts