Align with cdc-core lifecycle and strengthen supervisor coverage

- start processors before shareablizing
- propagate Runtime supervision options
- add lifecycle and supervisor regression tests
- cover worker failure edge cases
- eliminate hanging tests
- improve YARD documentation coverage

Author: kanutocd

lib/cdc/parallel.rb

@@ -12,6 +12,12 @@
 require_relative "parallel/router"
 require_relative "parallel/runtime"
 
+# Namespace for Change Data Capture ecosystem components.
+#
+# The `cdc-parallel` gem adds the {CDC::Parallel} runtime namespace under
+# this shared ecosystem root.
+#
+# @api public
 module CDC
   # Optional parallel Change Data Capture runtime for `cdc-core` processors.
   #

lib/cdc/parallel/configuration.rb

@@ -2,6 +2,10 @@
 
 module CDC
   module Parallel
+    # :nodoc:
+    ConfigurationData = Data.define(:size, :timeout)
+    private_constant :ConfigurationData
+
     # Immutable configuration shared by cdc-parallel runtime objects.
     #
     # `Configuration` validates worker sizing and timeout values at construction
@@ -22,7 +26,7 @@ module Parallel
     # @!attribute [r] timeout
     #   @return [Numeric, nil] Optional wait timeout in seconds.
     # @api public
-    class Configuration < Data.define(:size, :timeout)
+    class Configuration < ConfigurationData
       # Create a validated runtime configuration.
       #
       # @param size [Integer]