Handle parentheses in variables in commands

lib/kamal/secrets/dotenv/inline_command_substitution.rb

@@ -4,7 +4,7 @@ class Kamal::Secrets::Dotenv::InlineCommandSubstitution
       ::Dotenv::Parser.substitutions.map! { |sub| sub == ::Dotenv::Substitutions::Command ? self : sub }
     end
 
-    def call(value, _env, overwrite: false)
+    def call(value, env, overwrite: false)
       # Process interpolated shell commands
       value.gsub(Dotenv::Substitutions::Command.singleton_class::INTERPOLATED_SHELL_COMMAND) do |*|
         # Eliminate opening and closing parentheses
@@ -14,6 +14,7 @@ class Kamal::Secrets::Dotenv::InlineCommandSubstitution
           # Command is escaped, don't replace it.
           $LAST_MATCH_INFO[0][1..]
         else
+          command = ::Dotenv::Substitutions::Variable.call(command, env)
           if command =~ /\A\s*kamal\s*secrets\s+/
             # Inline the command
             inline_secrets_command(command)