feat(captain): store FAQ suggestion language

db/migrate/20260710000000_create_captain_faq_suggestions.rb

@@ -13,13 +13,15 @@ class CreateCaptainFaqSuggestions < ActiveRecord::Migration[7.1]
       t.vector :embedding, limit: 1536
       t.references :assistant, null: false, index: true
       t.references :account, null: false, index: true
+      t.string :language, null: false, default: 'en'
       t.integer :source_count, null: false, default: 0
       t.integer :status, null: false, default: 0
 
       t.timestamps
     end
 
-    add_index :captain_faq_suggestions, [:assistant_id, :status]
+    add_index :captain_faq_suggestions, [:assistant_id, :status, :language],
+              name: 'idx_captain_faq_suggestions_on_assistant_status_language'
     add_index :captain_faq_suggestions, :embedding, using: :ivfflat,
                                                     name: 'vector_idx_captain_faq_suggestions_embedding',
                                                     opclass: :vector_cosine_ops
@@ -31,6 +33,7 @@ class CreateCaptainFaqSuggestions < ActiveRecord::Migration[7.1]
       t.references :faq_suggestion, index: true
       t.string :generated_question, null: false
       t.text :generated_answer, null: false
+      t.string :language, null: false, default: 'en'
       t.integer :status, null: false, default: 0
 
       t.timestamps

db/schema.rb

@@ -397,6 +397,7 @@ ActiveRecord::Schema[7.1].define(version: 2026_07_10_000000) do
     t.bigint "faq_suggestion_id"
     t.string "generated_question", null: false
     t.text "generated_answer", null: false
+    t.string "language", default: "en", null: false
     t.integer "status", default: 0, null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
@@ -411,12 +412,13 @@ ActiveRecord::Schema[7.1].define(version: 2026_07_10_000000) do
     t.vector "embedding", limit: 1536
     t.bigint "assistant_id", null: false
     t.bigint "account_id", null: false
+    t.string "language", default: "en", null: false
     t.integer "source_count", default: 0, null: false
     t.integer "status", default: 0, null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["account_id"], name: "index_captain_faq_suggestions_on_account_id"
-    t.index ["assistant_id", "status"], name: "index_captain_faq_suggestions_on_assistant_id_and_status"
+    t.index ["assistant_id", "status", "language"], name: "idx_captain_faq_suggestions_on_assistant_status_language"
     t.index ["assistant_id"], name: "index_captain_faq_suggestions_on_assistant_id"
     t.index ["embedding"], name: "vector_idx_captain_faq_suggestions_embedding", opclass: :vector_cosine_ops, using: :ivfflat
   end

enterprise/app/models/captain/faq_observation.rb

@@ -5,6 +5,7 @@
 #  id                 :bigint           not null, primary key
 #  generated_answer   :text             not null
 #  generated_question :string           not null
+#  language           :string           default("en"), not null
 #  status             :integer          default("attached"), not null
 #  created_at         :datetime         not null
 #  updated_at         :datetime         not null
@@ -19,6 +20,6 @@ class Captain::FaqObservation < ApplicationRecord
 
   enum status: { attached: 0, discarded: 1 }
 
-  validates :generated_question, :generated_answer, presence: true
+  validates :generated_question, :generated_answer, :language, presence: true
   validates :faq_suggestion, presence: true, if: :attached?
 end

enterprise/app/models/captain/faq_suggestion.rb

@@ -5,6 +5,7 @@
 #  id           :bigint           not null, primary key
 #  answer       :text             not null
 #  embedding    :vector(1536)
+#  language     :string           default("en"), not null
 #  question     :string           not null
 #  source_count :integer          default(0), not null
 #  status       :integer          default("open"), not null
@@ -26,12 +27,13 @@ class Captain::FaqSuggestion < ApplicationRecord
 
   enum status: { open: 0, approved: 1, dismissed: 2 }
 
-  validates :question, :answer, presence: true
+  validates :question, :answer, :language, presence: true
 
   before_validation :ensure_account
   after_commit :update_embedding
 
   scope :ordered, -> { order(source_count: :desc, updated_at: :desc) }
+  scope :by_language, ->(language) { where(language: language) }
 
   private