Remove answer feedback model and table

This commit completes the removal of Useful/Not useful answer feedback.

It removes AnswerFeedback and its creation form, removes the answer
association and related eager loading, cleans up factories and specs,
and adds a migration to drop the answer_feedback table.

Author: chaecramb

app/controllers/conversations_controller.rb

@@ -42,7 +42,7 @@ def update
 
   def answer
     @question = Question.where(conversation: @conversation)
-                        .includes(answer: [{ sources: :chunk }, :feedback])
+                        .includes(answer: { sources: :chunk })
                         .find(params[:question_id])
     answer = @question.check_or_create_timeout_answer
 

app/models/answer.rb

@@ -55,7 +55,6 @@ def self.response_for_question_routing_label(label)
 
   belongs_to :question
   has_many :sources, -> { order(relevancy: :asc) }, class_name: "AnswerSource"
-  has_one :feedback, class_name: "AnswerFeedback"
   has_one :topics, class_name: "AnswerAnalysis::Topics"
   has_many :answer_relevancy_runs,
            -> { order(:created_at) },

app/models/answer_feedback.rb

@@ -24,7 +24,7 @@ def self.hashed_end_user_id(end_user_id)
 
   def questions_for_showing_conversation(only_answered: false, before_id: nil, after_id: nil, limit: nil)
     scope = Question.where(conversation: self)
-                  .includes(answer: [{ sources: :chunk }, :feedback])
+                  .includes(answer: { sources: :chunk })
                   .active
     scope = scope.joins(:answer) if only_answered
 

app/models/conversation.rb

@@ -51,7 +51,6 @@ def check_or_create_timeout_answer
       create_answer(
         message: Answer::CannedResponses::TIMED_OUT_RESPONSE,
         status: :error_timeout,
-        feedback: nil,
       )
     end
   end

app/models/form/create_answer_feedback.rb

@@ -0,0 +1,16 @@
+class DropAnswerFeedback < ActiveRecord::Migration[8.0]
+  def up
+    drop_table :answer_feedback
+  end
+
+  def down
+    create_table :answer_feedback, id: :uuid do |t|
+      t.references :answer, type: :uuid, null: false, index: { unique: true }, foreign_key: { on_delete: :cascade }
+      t.boolean :useful, null: false
+
+      t.timestamps
+    end
+
+    add_index :answer_feedback, :created_at
+  end
+end

app/models/question.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2026_04_17_081153) do
+ActiveRecord::Schema[8.1].define(version: 2026_04_27_093000) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "citext"
   enable_extension "pg_catalog.plpgsql"
@@ -91,15 +91,6 @@
     t.index ["answer_id"], name: "index_answer_analysis_topics_on_answer_id", unique: true
   end
 
-  create_table "answer_feedback", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
-    t.uuid "answer_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.boolean "useful", null: false
-    t.index ["answer_id"], name: "index_answer_feedback_on_answer_id", unique: true
-    t.index ["created_at"], name: "index_answer_feedback_on_created_at"
-  end
-
   create_table "answer_source_chunks", id: :uuid, default: -> { "gen_random_uuid()" }, force: :cascade do |t|
     t.string "base_path", null: false
     t.integer "chunk_index", null: false
@@ -232,7 +223,6 @@
   add_foreign_key "answer_analysis_context_relevancy_runs", "answers", on_delete: :cascade
   add_foreign_key "answer_analysis_faithfulness_runs", "answers", on_delete: :cascade
   add_foreign_key "answer_analysis_topics", "answers", on_delete: :cascade
-  add_foreign_key "answer_feedback", "answers", on_delete: :cascade
   add_foreign_key "answer_sources", "answer_source_chunks", on_delete: :restrict
   add_foreign_key "answer_sources", "answers", on_delete: :cascade
   add_foreign_key "answers", "questions", on_delete: :cascade

db/migrate/20260427093000_drop_answer_feedback.rb

@@ -5,7 +5,6 @@
     status { :answered }
     completeness { :complete }
     sources { [] }
-    feedback { nil }
     topics { nil }
 
     trait :with_sources do
@@ -25,10 +24,6 @@
       end
     end
 
-    trait :with_feedback do
-      feedback { build(:answer_feedback) }
-    end
-
     trait :with_topics do
       topics { build(:answer_analysis_topics) }
     end