Migrate create_post_file_fingerprints rake task to typed class

- Extract rake task logic into Tasks::CreatePostFileFingerprintsTask class
- Add full Sorbet strict typing with comprehensive method signatures
- Implement Mode enum with proper string serialization for execution modes
- Inherit from InterruptableTask for signal handling (SIGINT/SIGTERM)
- Add comprehensive test coverage with 24 examples covering all modes
- Update Rakefile to instantiate and use the new task class
- Support all existing execution modes: post_file_descending, posts_descending, user, users_descending
- Maintain backward compatibility with existing environment variable interface

Rakefile

@@ -293,120 +293,22 @@ task run_fa_user_avatar_jobs: :environment do
 end
 
 task create_post_file_fingerprints: %i[environment set_logger_stdout] do
-  PB_FORMAT = "%B %c/%C (%r/sec) %J%% %a %E"
+  task = Tasks::CreatePostFileFingerprintsTask.new
 
-  def migrate_posts_for_user(user)
-    puts "migrating posts for #{user.to_param}"
-    posts = user.posts.includes(files: %i[blob thumbnails bit_fingerprints])
-
-    pb =
-      ProgressBar.create(
-        total: posts.count,
-        progress_mark: " ",
-        remainder_mark: " ",
-        format: PB_FORMAT,
-      )
-
-    posts.find_in_batches(batch_size: 64) do |batch|
-      ReduxApplicationRecord.transaction do
-        batch.each do |post|
-          migrate_post(post)
-          pb.progress = [pb.progress + 1, pb.total].min
-        end
-      end
+  mode =
+    if ENV["post_file_descending"].present?
+      Tasks::CreatePostFileFingerprintsTask::Mode::PostFileDescending
+    elsif ENV["posts_descending"].present?
+      Tasks::CreatePostFileFingerprintsTask::Mode::PostsDescending
+    elsif ENV["user"].present?
+      Tasks::CreatePostFileFingerprintsTask::Mode::User
+    elsif ENV["users_descending"].present?
+      Tasks::CreatePostFileFingerprintsTask::Mode::UsersDescending
+    else
+      raise "need one of: post_file_descending, posts_descending, user, users_descending"
     end
-  end
 
-  def migrate_post(post)
-    puts "#{post.creator&.url_name} (#{post.creator&.user_user_follows_to_count}) :: #{post.to_param} / '#{post.title_for_view}'"
-    ColorLogger.quiet do
-      post.files.each do |file|
-        migrate_post_file(file)
-      rescue StandardError => e
-        puts "error: #{e.message}"
-      end
-    end
-  end
-
-  def migrate_post_file(post_file)
-    ColorLogger.quiet do
-      Domain::PostFileThumbnailJob.new.perform({ post_file: })
-    rescue => e
-      puts "error: #{e.message}"
-    end
-  end
-
-  if ENV["post_file_descending"].present?
-    total = 49_783_962 # cache this value
-    pb =
-      ProgressBar.create(
-        total:,
-        progress_mark: " ",
-        remainder_mark: " ",
-        format: PB_FORMAT,
-      )
-    i = 0
-    Domain::PostFile
-      .where(state: "ok")
-      .includes(:blob)
-      .find_each(
-        order: :desc,
-        batch_size: 32,
-        start: ENV["start_at"],
-      ) do |post_file|
-        i += 1
-        if i % 100 == 0
-          post = post_file.post
-          creator_str =
-            (post.class.has_creators? ? post.creator.to_param : "(none)")
-          post_desc =
-            "#{creator_str&.rjust(20)} / #{post_file.post&.to_param}".ljust(40)
-          puts "post_file = #{post_file.id} :: #{post_desc} - #{post_file.post.title_for_view}"
-        end
-        migrate_post_file(post_file)
-        pb.progress = [pb.progress + 1, pb.total].min
-      end
-  elsif ENV["posts_descending"].present?
-    # total = Domain::Post.count
-    total = 66_431_808 # cache this value
-    pb =
-      ProgressBar.create(
-        total:,
-        progress_mark: " ",
-        remainder_mark: " ",
-        format: PB_FORMAT,
-      )
-    Domain::Post.find_each(order: :desc) do |post|
-      migrate_post(post) unless post.is_a?(Domain::Post::InkbunnyPost)
-      pb.progress = [pb.progress + 1, pb.total].min
-    end
-  elsif ENV["user"].present?
-    for_user = ENV["user"] || raise("need 'user'")
-    user = DomainController.find_model_from_param(Domain::User, for_user)
-    raise "user '#{for_user}' not found" unless user
-    migrate_posts_for_user(user)
-  elsif ENV["users_descending"].present?
-    # all users with posts, ordered by post count descending
-    migrated_file = File.open("migrated_files.txt", "a+")
-    migrated_file.seek(0)
-    migrated_users = migrated_file.readlines.map(&:strip)
-    users =
-      Domain::User::FaUser.order(
-        Arel.sql("user_user_follows_to_count DESC NULLS LAST"),
-      ).pluck(:id)
-
-    users.each do |user_id|
-      user = Domain::User::FaUser.find(user_id)
-      next if migrated_users.include?(user.to_param)
-      puts "migrating posts for #{user.to_param} (#{user.num_watched_by} watched by)"
-      migrate_posts_for_user(user)
-      migrated_file.write("#{user.to_param}\n")
-      migrated_file.flush
-    end
-    migrated_file.close
-  else
-    raise "need 'user' or 'users_descending'"
-  end
+  task.run(mode: mode, user_param: ENV["user"], start_at: ENV["start_at"])
 end
 
 task enqueue_pending_post_files: :environment do