Add debug gem as a development dependency

Gemfile.lock

@@ -9,7 +9,14 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
+    debug (1.9.2)
+      irb (~> 1.10)
+      reline (>= 0.3.8)
     diff-lcs (1.5.1)
+    io-console (0.7.2)
+    irb (1.14.0)
+      rdoc (>= 4.0.0)
+      reline (>= 0.4.2)
     json (2.7.2)
     language_server-protocol (3.17.0.3)
     lint_roller (1.1.0)
@@ -18,9 +25,15 @@ GEM
       ast (~> 2.4.1)
       racc
     phlex (1.11.0)
+    psych (5.1.2)
+      stringio
     racc (1.8.1)
     rainbow (3.1.1)
+    rdoc (6.7.0)
+      psych (>= 4.0.0)
     regexp_parser (2.9.2)
+    reline (0.5.9)
+      io-console (~> 0.5)
     rexml (3.3.3)
       strscan
     rspec (3.13.0)
@@ -65,6 +78,7 @@ GEM
     standard-performance (1.4.0)
       lint_roller (~> 1.1)
       rubocop-performance (~> 1.21.0)
+    stringio (3.1.1)
     strscan (3.1.0)
     unicode-display_width (2.5.0)
     zeitwerk (2.6.17)
@@ -74,6 +88,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  debug (~> 1.9, >= 1.9.2)
   phlexy_ui!
   rspec (~> 3.13.0)
   standard (~> 1.39.2)

phlexy_ui.gemspec

@@ -17,4 +17,5 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency "standard", "~> 1.39.2"
   s.add_development_dependency "rspec", "~> 3.13.0"
+  s.add_development_dependency "debug", "~> 1.9", ">= 1.9.2"
 end