Do-Not-Restructure Zone

These should not be structurally changed in first-pass UI work: - Editor internals for /pad/, /code/, /doc/, /sheet/, /presentation/ - Realtime collaboration internals - Sandbox iframe internals - Worker routes - OnlyOffice wrappers - Cryptographic/login/session logic - Websocket/network logic

Allowed here: - Light theme/shell treatment around the tools - Icon/color treatment - External wrapper styling if it does not interfere with editors

Avoid: - Core JS edits under /cryptpad/www - Replacing editor markup - Third-party scripts - Remote embeds - CSP changes unless explicitly required and reviewed