- Add main_content.rml for sandbox-test app with test cards for Timer, JSON, Crypto, Storage - Add sandbox test functions to shell.lua (testSandboxTimer, testSandboxJSON, etc.) - Register sandbox-test in builtin_ids and shellNavigateTo paths - Add sandbox-test styles to shell.rml Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>