add revisions

db/migrate/20260506121640_create_template_versions.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+class CreateTemplateVersions < ActiveRecord::Migration[8.1]
+  def change
+    create_table :template_versions do |t|
+      t.references :template, null: false, foreign_key: true, index: false
+      t.references :account, null: false, foreign_key: true, index: true
+      t.references :author, null: false, foreign_key: { to_table: :users }, index: true
+      t.text :data, null: false
+      t.string :sha1, null: false
+      t.timestamps
+    end
+
+    add_index :template_versions, %i[template_id sha1], unique: true
+  end
+end

db/schema.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_05_06_120000) do
+ActiveRecord::Schema[8.1].define(version: 2026_05_06_121640) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "btree_gin"
   enable_extension "pg_catalog.plpgsql"
@@ -444,6 +444,19 @@ ActiveRecord::Schema[8.1].define(version: 2026_05_06_120000) do
     t.index ["template_id"], name: "index_template_sharings_on_template_id"
   end
 
+  create_table "template_versions", force: :cascade do |t|
+    t.bigint "account_id", null: false
+    t.bigint "author_id", null: false
+    t.datetime "created_at", null: false
+    t.text "data", null: false
+    t.string "sha1", null: false
+    t.bigint "template_id", null: false
+    t.datetime "updated_at", null: false
+    t.index ["account_id"], name: "index_template_versions_on_account_id"
+    t.index ["author_id"], name: "index_template_versions_on_author_id"
+    t.index ["template_id", "sha1"], name: "index_template_versions_on_template_id_and_sha1", unique: true
+  end
+
   create_table "templates", force: :cascade do |t|
     t.bigint "account_id", null: false
     t.datetime "archived_at"
@@ -587,6 +600,9 @@ ActiveRecord::Schema[8.1].define(version: 2026_05_06_120000) do
   add_foreign_key "template_folders", "template_folders", column: "parent_folder_id"
   add_foreign_key "template_folders", "users", column: "author_id"
   add_foreign_key "template_sharings", "templates"
+  add_foreign_key "template_versions", "accounts"
+  add_foreign_key "template_versions", "templates"
+  add_foreign_key "template_versions", "users", column: "author_id"
   add_foreign_key "templates", "accounts"
   add_foreign_key "templates", "template_folders", column: "folder_id"
   add_foreign_key "templates", "users", column: "author_id"