Update knip.ts for new monorepo structure

Updated workspace configuration for spec/dummy to react_on_rails/spec/dummy after
the monorepo restructure.

Changes:
- Renamed workspace from 'spec/dummy' to 'react_on_rails/spec/dummy'
- Updated playwright workflow path reference: ../../ → ../../../
- Added vendor/bundle/** to ignore (prevent analyzing bundled gems)
- Added spec/** to ignore (test files)
- Added babel.config.js to ignore (requires dummy app dependencies)

This fixes Knip dead code detection which was analyzing files in vendor/bundle
(bundled gem dependencies) that aren't part of the project's actual dependencies.

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

Co-Authored-By: Claude <[email protected]>

Author: justin808

knip.ts

@@ -120,13 +120,12 @@ const config: KnipConfig = {
         'src/streamServerRenderedReactComponent.ts:StreamingTrackers',
       ],
     },
-    'spec/dummy': {
+    'react_on_rails/spec/dummy': {
       entry: [
         'app/assets/config/manifest.js!',
         'client/app/packs/**/*.js!',
         // Not sure why this isn't detected as a dependency of client/app/packs/server-bundle.js
         'client/app/generated/server-bundle-generated.js!',
-        'spec/fixtures/automated_packs_generation/**/*.js{x,}',
         'config/webpack/{production,development,test}.js',
         // Declaring this as webpack.config instead doesn't work correctly
         'config/webpack/webpack.config.js',
@@ -136,10 +135,17 @@ const config: KnipConfig = {
         'e2e/playwright.config.js',
         'e2e/playwright/e2e/**/*.spec.js',
         // CI workflow files that reference package.json scripts
-        '../../.github/workflows/playwright.yml',
+        '../../../.github/workflows/playwright.yml',
       ],
       ignore: [
         '**/app-react16/**/*',
+        // Bundled gems should not be analyzed by Knip
+        'vendor/bundle/**',
+        // Test files that shouldn't be treated as entry points
+        'tests/**',
+        'spec/**',
+        // Config files that require dependencies not in workspace root
+        'babel.config.js',
         // Playwright support files and helpers - generated by cypress-on-rails gem
         'e2e/playwright/support/**',
         // Components and files used dynamically by React on Rails (registered at runtime)