Fix Jest integration in CI - add Jest to test scripts

Jest was not being run in CI at all! The test:client script was broken
(tried to cd to client/ which has no package.json).

Changes:
- Fixed test:client to run 'yarn jest' directly
- Added jest to main test script (build:test && lint && jest)
- Now our SWC configuration test will actually be run in CI

This ensures that client/__tests__/swc-config.spec.js and all other
Jest tests are executed as part of the test suite.

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

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

Author: justin808

package.json

@@ -24,8 +24,8 @@
     "lint:eslint": "yarn eslint client --ext \".js,.jsx,.ts\"",
     "lint:prettier": "yarn prettier \"**/*.@(js|jsx)\" --list-different",
     "lint": " yarn lint:eslint --fix && yarn lint:prettier --w",
-    "test": "yarn build:test && yarn lint",
-    "test:client": "cd client && yarn test",
+    "test": "yarn build:test && yarn lint && yarn jest",
+    "test:client": "yarn jest",
     "build:test": "rm -rf public/packs-test && RAILS_ENV=test NODE_ENV=test bin/shakapacker",
     "build:dev": "rm -rf public/packs && RAILS_ENV=development NODE_ENV=development bin/shakapacker",
     "build:clean": "rm -rf public/packs || true"