CLDC-4202: Add a rake to populate new question numbers

we can run this rake to automatically add all the question numbers at the start of a new year, which should simplify the process a lot

lib/tasks/add_new_year_to_questions.rake

@@ -0,0 +1,55 @@
+require "pathname"
+
+desc "Add a new year to all lettings question number hashes and saves the new code.
+Usage: bundle exec rake add_new_year_to_questions[new_year,log_type].
+Example: bundle exec rake add_new_year_to_questions[2027,lettings].
+This rake should only be run as part of local development at the start of new collection year creation.
+Make sure your working tree is clean before running this, it will update each question file in place.
+Note that this will only update questions with a QUESTION_NUMBER_FROM_YEAR hash set.
+Some questions (such as any of the per person questions) which define custom question logic will need manual review.
+Params:
+- new_year: the year to add, e.g. 2025
+- log_type: the type of log to update. can be lettings or sales"
+task :add_new_year_to_questions, %i[new_year log_type] => :environment do |_task, args|
+  new_year = args[:new_year].to_i
+  previous_year = new_year - 1
+
+  root = Pathname.new("app/models/form/#{args[:log_type]}/questions")
+  files = root.glob("*.rb")
+
+  hash_re = /QUESTION_NUMBER_FROM_YEAR\s*=\s*\{([^}]*)}\.freeze/m
+
+  changed = []
+
+  files.each do |path|
+    text = path.read
+    next unless text.include?("QUESTION_NUMBER_FROM_YEAR")
+
+    match = hash_re.match(text)
+    next unless match
+
+    body = match[1]
+    pairs = body.scan(/(\d+)\s*=>\s*(\d+)/)
+    next if pairs.empty?
+
+    year_to_num = pairs.to_h { |y, n| [y.to_i, n.to_i] }
+    next if year_to_num.key?(new_year)
+    next unless year_to_num.key?(previous_year)
+
+    year_to_num[new_year] = year_to_num[previous_year]
+
+    items = year_to_num.keys.sort.map { |y| "#{y} => #{year_to_num[y]}" }.join(", ")
+    replacement = "QUESTION_NUMBER_FROM_YEAR = { #{items} }.freeze"
+
+    new_text = text.sub(hash_re, replacement)
+
+    next if new_text == text
+
+    path.write(new_text)
+    changed << path
+  end
+
+  puts "changed #{changed.length}"
+  changed.each { |p| puts p }
+end
+