- add CodeBlock for read-only syntax-highlighted display (hljs, js/json)
- add CodeEditor wrapping Monaco editor with theme sync, focus state, and error state
- replace code textareas in snippet, credential, and step pages with CodeEditor
- replace code <pre> blocks in snippet and credential detail pages with CodeBlock
- make form cards full-width on pages with code editors
- add resize:vertical support to CodeEditor wrapper with automaticLayout
- add nullable title column to scenario steps; exposed in create/edit forms and step table
- add scenario-credential join (many-to-many with CredentialEntity) with CRUD endpoints
- expose environment URLs in code executor helpers via helpers.env and helpers.getEnvUrl()
- resolve and cache environment per run from the login step's environmentName in scheduler
- add section spacing and step table title column to ScenarioDetailPage
ars9