docs(ci): complete bun/turborepo/changesets migration docs and workflows

- Update all CI workflows (pre-commit, tech-debt) to use Bun
- Update build scripts (js_build.sh, cypress_build.sh, eslint.sh) for Bun
- Add sync-package-versions.js script for release version alignment
- Simplify package.json scripts (build:packages, publish:packages)
- Add gitTag: false to changesets config to avoid repo tag clutter
- Remove obsolete Lerna scripts (build.js, lernaVersion.sh)
- Update RELEASING/README.md with comprehensive npm publishing guide
- Update all developer documentation for Bun usage
- Update LLM instruction files (AGENTS.md, dev-standard.mdc)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/developer_portal/testing/frontend-testing.md

@@ -44,16 +44,16 @@ Comprehensive guide for testing Superset's frontend components and features.
 
 ```bash
 # Run all frontend tests
-npm run test
+bun run test
 
 # Run tests in watch mode
-npm run test -- --watch
+bun run test -- --watch
 
 # Run tests with coverage
-npm run test -- --coverage
+bun run test -- --coverage
 
 # Run specific test file
-npm run test -- MyComponent.test.tsx
+bun run test -- MyComponent.test.tsx
 ```
 
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