Replying to / forwarding a layout-heavy HTML email (nested tables, MJML,
Outlook divs) destroyed its layout: ProseMirror re-parsed the quoted body
through its strict schema and discarded anything that didn't fit. The quoted
original is now held verbatim in a new atomic QuotedHtml node and never parsed
into the schema; its NodeView renders inside a shadow root so app CSS can't
cascade in and the in-editor view matches the sent mail 1:1.
- quoted-html.ts (new): QuotedHtml atom node + shadow-DOM NodeView (inner
contentEditable for redaction), serializeEditorContent(), buildQuotedHtmlBlock().
- rich-text-editor: register the node; emit via serializeEditorContent (not
getHTML) so the verbatim island survives.
- composer: both HTML reply/forward paths embed the original as an island
(sanitize -> cid-rewrite -> buildQuotedHtmlBlock); the signature-swap effect
serializes via serializeEditorContent and treats the island as a quote
boundary so the splice never cuts into the quoted body.
atom:true means Backspace at the boundary / Ctrl+A+Delete removes the whole
quote in one go.
