Fixes https://github.com/twentyhq/twenty/issues/19899
Front component iframes were previously forced to `sandbox=""`, which
fully locks them down: no scripts, no forms, no popups. That broke any
legitimate embedded content (maps, widgets, embeds) developers tried to
render.
But we can't just trust the app-provided sandbox value either: tokens
like allow-same-origin or allow-top-navigation would let a malicious
embed escape the sandbox and hijack the host Twenty tab.
- Add `sanitizeIframeSandbox`, which keeps the iframe useful while
enforcing security:
applies a safe default (allow-scripts allow-forms allow-popups) when no
sandbox is set
always forces allow-scripts so embeds work
- strips dangerous tokens (`allow-same-origin`, all
`allow-top-navigation`*, `allow-popups-to-escape-sandbox`),
case-insensitively
- Wire it into `createHtmlHostWrapper` so every `iframe` rendered by a
front component is sanitized.
- Add unit tests for the sanitizer and Storybook interaction tests
asserting dangerous sandboxes are stripped.
