try to fix heroku deployment, copying TEF-108

Dockerfile

@@ -43,7 +43,7 @@ RUN curl -sL https://github.com/nodenv/node-build/archive/master.tar.gz | tar xz
     rm -rf /tmp/node-build-master
 
 # Install application gems
-COPY Gemfile Gemfile.lock ./
+COPY .ruby-version Gemfile Gemfile.lock ./
 RUN bundle install && \
     rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
     bundle exec bootsnap precompile --gemfile

Gemfile

@@ -1,5 +1,8 @@
 source "https://rubygems.org"
 
+ruby_version = File.read(File.join(File.dirname(__FILE__), ".ruby-version")).strip
+ruby ruby_version
+
 # Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
 gem "rails", "~> 8.0.2", ">= 8.0.2.1"
 # The modern asset pipeline for Rails [https://github.com/rails/propshaft]

Gemfile.lock

@@ -370,5 +370,8 @@ DEPENDENCIES
   view_component (~> 4.0)
   web-console
 
+RUBY VERSION
+   ruby 3.4.5p51
+
 BUNDLED WITH
    2.6.9

app.json

@@ -0,0 +1,10 @@
+{
+  "buildpacks": [
+    {
+      "url": "heroku/nodejs"
+    },
+    {
+      "url": "heroku/ruby"
+    }
+  ]
+}

package.json

@@ -8,6 +8,10 @@
     "node": "^20.19.5",
     "tailwindcss": "^4.1.14"
   },
+  "engines": {
+    "node": "20.x",
+    "yarn": "1.x"
+  },
   "scripts": {
     "build:css": "npx @tailwindcss/cli -i ./app/assets/stylesheets/application.tailwind.css -o ./app/assets/builds/application.css --minify",
     "build": "esbuild app/javascript/*.* --bundle --sourcemap --format=esm --outdir=app/assets/builds --public-path=/assets"