rubocop and improved lang support

Gemfile.lock

@@ -1,10 +1,20 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    ast (2.4.3)
     base64 (0.2.0)
+    json (2.12.2)
+    language_server-protocol (3.17.0.5)
+    lint_roller (1.1.0)
     logger (1.7.0)
     mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
+    parallel (1.27.0)
+    parser (3.3.8.0)
+      ast (~> 2.4.1)
+      racc
+    prism (1.4.0)
+    racc (1.8.1)
     rack (3.1.14)
     rack-accept (0.4.5)
       rack (>= 0.4)
@@ -15,6 +25,23 @@ GEM
     rack-session (2.1.1)
       base64 (>= 0.1.0)
       rack (>= 3.0.0)
+    rainbow (3.1.1)
+    regexp_parser (2.10.0)
+    rubocop (1.75.7)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
+      parallel (~> 1.10)
+      parser (>= 3.3.0.2)
+      rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.44.0, < 2.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.44.1)
+      parser (>= 3.3.7.2)
+      prism (~> 1.4)
+    ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
     sinatra (4.1.1)
       logger (>= 1.6.0)
@@ -24,6 +51,9 @@ GEM
       rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
     tilt (2.6.0)
+    unicode-display_width (3.1.4)
+      unicode-emoji (~> 4.0, >= 4.0.4)
+    unicode-emoji (4.0.4)
 
 PLATFORMS
   ruby
@@ -31,6 +61,7 @@ PLATFORMS
 
 DEPENDENCIES
   rack-accept (~> 0.4.5)
+  rubocop
   sinatra (~> 4.1)
 
 BUNDLED WITH