Fix file viewer: block name mismatch (extra_scripts → scripts)

Fix file viewer + template syntax + requirements.txt generation

Fix file tree code viewer — selectFile now renders content on click

Add Ollama + OllaBridge to provider dropdown in Configure step

Add sandbox verification toggle with local+MatrixLab fallback

v0.2.1 production RC — AST security validator, OutputTier, reference validation

v0.2.0: production infrastructure — spec-first generators, security validator, ArtifactBundle