feat: add extended language validators and fix tokenizer crash bugs

Expand nimcheck with validators and tokenizers for C, C++, C#, Go, Rust,
Ruby, CSS, SQL, Markdown, Dockerfile, Makefile, Kotlin, Lua, Swift,
TypeScript, and XML. Register all flavors in the validator factory and
improve auto-detection scoring for the new languages.

Fix infinite tokenizer loops that caused OOM kills: closeBracket now
advances position, finishTokenizeStep guards stalled tokenization, and
Jinja/JS tokenizers no longer double-advance on brackets.

Fix block-balance false positives in Lua (for/do) and Ruby (postfix
unless), SQL trailing-comma detection across whitespace, and Makefile
tab literals in test fixtures.

tests/fixtures/ruby/edge_cases.rb

@@ -0,0 +1,66 @@
+module EnumerableExtensions
+  refine Array do
+    def second
+      self[1]
+    end
+
+    def middle
+      self[size / 2]
+    end
+  end
+end
+
+using EnumerableExtensions
+
+class Singleton
+  private_class_method :new
+
+  @instance = nil
+
+  def self.instance
+    @instance ||= new
+  end
+end
+
+module_function
+
+def log(level, message)
+  warn "[#{level.upcase}] #{message}"
+end
+
+require "ostruct"
+require "set"
+require "delegate"
+
+Point = Struct.new(:x, :y, keyword_init: true)
+p = Point.new(x: 10, y: 20)
+
+class Stack
+  include Enumerable
+
+  def initialize
+    @items = []
+  end
+
+  def push(item)
+    @items.push(item)
+  end
+
+  def pop
+    @items.pop
+  end
+
+  def each(&block)
+    @items.each(&block)
+  end
+end
+
+s = Stack.new
+s.push(1)
+s.push(2)
+s.each { |i| puts i }
+
+$global_count = 0
+DEFAULT_TIMEOUT = 30
+
+puts "Global: #{$global_count}, Timeout: #{DEFAULT_TIMEOUT}"

tests/fixtures/ruby/invalid.rb

@@ -0,0 +1,12 @@
+class Broken
+  attr_accessor :x
+
+  def missing_end
+    if x > 0
+      puts "positive"
+
+  def wrong_syntax
+    x = 42
+    {x + 1
+
+end

tests/fixtures/ruby/valid.rb

@@ -0,0 +1,80 @@
+#!/usr/bin/env ruby
+require "json"
+require "net/http"
+require "uri"
+
+class User
+  attr_accessor :id, :name, :email, :active
+
+  def initialize(id:, name:, email:, active: true)
+    @id = id
+    @name = name
+    @email = email
+    @active = active
+  end
+
+  def to_s
+    "#{@name} <#{@email}>"
+  end
+
+  def active?
+    @active
+  end
+
+  def deactivate!
+    @active = false
+  end
+end
+
+class UserRepository
+  def initialize
+    @users = {}
+  end
+
+  def add(user)
+    @users[user.id] = user
+  end
+
+  def find(id)
+    @users[id]
+  end
+
+  def find_by_email(email)
+    @users.values.find { |u| u.email == email }
+  end
+
+  def active_users
+    @users.values.select(&:active?)
+  end
+
+  def each(&block)
+    @users.values.each(&block)
+  end
+
+  def to_json(*args)
+    @users.values.map(&:to_h).to_json(*args)
+  end
+end
+
+def fetch_users(url)
+  uri = URI.parse(url)
+  response = Net::HTTP.get_response(uri)
+  raise "HTTP error: #{response.code}" unless response.is_a?(Net::HTTPSuccess)
+  JSON.parse(response.body)
+rescue StandardError => e
+  warn "Failed to fetch users: #{e.message}"
+  []
+end
+
+def process_items(items)
+  items.map { |item| yield item }
+end
+
+repo = UserRepository.new
+repo.add(User.new(id: 1, name: "Alice", email: "alice@example.com"))
+
+repo.each do |user|
+  puts user.to_s
+end
+
+puts "Active: #{repo.active_users.size}"