feat: migrations for document auto-sync [AI-141] (#14041)

# Pull Request Template

## Description

Add migrations for document auto-sync

Fixes # (issue)

## Type of change

- [x] New feature (non-breaking change which adds functionality)

## How Has This Been Tested?
locally

## Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [x] Any dependent changes have been merged and published in downstream
modules

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2026_04_09_091202) do
+ActiveRecord::Schema[7.1].define(version: 2026_04_10_092753) do
   # These extensions should be enabled to support this database
   enable_extension "pg_stat_statements"
   enable_extension "pg_trgm"
@@ -329,6 +329,7 @@ ActiveRecord::Schema[7.1].define(version: 2026_04_09_091202) do
     t.datetime "updated_at", null: false
     t.integer "status", default: 1, null: false
     t.string "documentable_type"
+    t.boolean "edited", default: false, null: false
     t.index ["account_id"], name: "index_captain_assistant_responses_on_account_id"
     t.index ["assistant_id"], name: "index_captain_assistant_responses_on_assistant_id"
     t.index ["documentable_id", "documentable_type"], name: "idx_cap_asst_resp_on_documentable"
@@ -377,10 +378,14 @@ ActiveRecord::Schema[7.1].define(version: 2026_04_09_091202) do
     t.datetime "updated_at", null: false
     t.integer "status", default: 0, null: false
     t.jsonb "metadata", default: {}
+    t.integer "sync_status"
+    t.datetime "last_synced_at"
+    t.datetime "last_sync_attempted_at"
     t.index ["account_id"], name: "index_captain_documents_on_account_id"
     t.index ["assistant_id", "external_link"], name: "index_captain_documents_on_assistant_id_and_external_link", unique: true
     t.index ["assistant_id"], name: "index_captain_documents_on_assistant_id"
     t.index ["status"], name: "index_captain_documents_on_status"
+    t.index ["account_id", "sync_status"], name: "index_captain_documents_on_account_id_and_sync_status"
   end
 
   create_table "captain_inboxes", force: :cascade do |t|