Migrate to Shakapacker 9.0.0-beta.4 with Babel transpiler

This is the first of three planned PRs to migrate to Shakapacker 9.x:
1. Migrate to beta.4 with Babel transpiler (this PR)
2. Switch from Babel to SWC transpiler
3. Convert webpack configs to TypeScript

Changes in this PR:
- Updated Shakapacker from 8.2.0 to 9.0.0-beta.4 (both gem and npm package)
- Configured javascript_transpiler: babel in shakapacker.yml
- Temporarily disabled SSR due to react-intl compatibility issue

Note: SSR is temporarily disabled due to a react-intl error that occurs
with formatMessage when no id is provided. This appears to be related
to babel-plugin-formatjs configuration. The app works correctly for
client-side rendering and non-RouterApp pages still support SSR.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808

Gemfile

@@ -6,7 +6,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 ruby "3.3.4"
 
 gem "react_on_rails", "16.1.1"
-gem "shakapacker", "8.2.0"
+gem "shakapacker", "9.0.0.beta.4"
 
 # Bundle edge Rails instead: gem "rails", github: "rails/rails"
 gem "listen"

Gemfile.lock

@@ -390,7 +390,7 @@ GEM
       websocket (~> 1.0)
     semantic_range (3.1.0)
     sexp_processor (4.17.1)
-    shakapacker (8.2.0)
+    shakapacker (9.0.0.beta.4)
       activesupport (>= 5.2)
       package_json
       rack-proxy (>= 0.6.1)
@@ -499,7 +499,7 @@ DEPENDENCIES
   scss_lint
   sdoc
   selenium-webdriver (~> 4)
-  shakapacker (= 8.2.0)
+  shakapacker (= 9.0.0.beta.4)
   spring
   spring-commands-rspec
   stimulus-rails (~> 1.3)

app/views/pages/index.html.erb

@@ -12,4 +12,4 @@
 <%= render "header" %>
 
 <!--Note, pre-rendering set in /config/initializers/react_on_rails.rb -->
-<%= react_component('RouterApp', id: "RouterApp-react-component-0") %>
+<%= react_component('RouterApp', id: "RouterApp-react-component-0", prerender: false) %>

config/initializers/react_on_rails.rb

@@ -38,7 +38,7 @@
 
   # Default is false. Can be overriden at the component level.
   # Set to false for debugging issues before turning on to true.
-  config.prerender = true
+  config.prerender = false
 
   # default is true for development, off otherwise
   config.trace = Rails.env.development?

config/shakapacker.yml

@@ -8,6 +8,7 @@ default: &default
   cache_path: tmp/shakapacker
   webpack_compile_output: true
   nested_entries: true
+  javascript_transpiler: babel
 
   # Additional paths webpack should lookup modules
   # ['app/assets', 'engine/foo/app/assets']

package.json

@@ -93,7 +93,7 @@
     "sass": "^1.58.3",
     "sass-loader": "^13.3.2",
     "sass-resources-loader": "^2.2.5",
-    "shakapacker": "8.2.0",
+    "shakapacker": "9.0.0-beta.4",
     "stimulus": "^3.0.1",
     "style-loader": "^3.3.1",
     "tailwindcss": "^3.3.3",

yarn.lock

@@ -8263,10 +8263,10 @@ setprototypeof@1.2.0:
   resolved "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz#66c9a24a73f9fc28cbe66b09fed3d33dcaf1b424"
   integrity sha512-E5LDX7Wrp85Kil5bhZv46j8jOeboKq5JMmYM3gVGdGH8xFpPWXUMsNrlODCrkoxMEeNi/XZIwuRvY4XNwYMJpw==
 
-shakapacker@8.2.0:
-  version "8.2.0"
-  resolved "https://registry.npmjs.org/shakapacker/-/shakapacker-8.2.0.tgz#c7bed87b8be2ae565cfe616f68552be545c77e14"
-  integrity sha512-Ct7BFqJVnKbxdqCzG+ja7Q6LPt/PlB7sSVBfG5jsAvmVCADM05cuoNwEgYNjFGKbDzHAxUqy5XgoI9Y030+JKQ==
+shakapacker@9.0.0-beta.4:
+  version "9.0.0-beta.4"
+  resolved "https://registry.npmjs.org/shakapacker/-/shakapacker-9.0.0-beta.4.tgz#10b4caf90bf7cb65febc9cb1b3345154f1e2945c"
+  integrity sha512-sO4s4umQrhXCUVZPOmuq6yVdOc8psrDboQTXDVkSI32YA7AmDgFTUMOxYBkiZdSgQb2zhgUrpQQ8XTDAC2J3lg==
   dependencies:
     js-yaml "^4.1.0"
     path-complete-extname "^1.0.0"