Icon Request: book-text-vertical & book-open-text-vertical

### Icon name book-text-vertical, book-open-text-vertical ### Use cases Vertical writing (top-to-bottom, right-to-left) is the standard typesetting mode for a large portion of Japanese, Traditional Chinese, and Mongolian publishing — including most novels, manga, newspapers, and classical texts. CSS supports it natively via `writing-mode: vertical-rl`. Real use cases where the existing `book-text` / `book-open-text` icons fall short because their text strokes are horizontal: 1. Reading-mode toggle in e-readers and reading apps for Japanese/Chinese literature. Apps like Kindle (JP edition), Apple Books (JP), and readers for 青空文庫 (Aozora Bunko, the Japanese equivalent of Project Gutenberg) let users switch between horizontal and vertical layouts. A horizontal/vertical icon pair is the natural way to represent that toggle, but today only the horizontal version exists. 2. Document-type indicators in writing tools and CMSes targeting Japanese authors. Novel-writing apps, manga script editors, and Japanese-language CMSes need to distinguish vertical-text documents (novels, traditional essays) from horizontal ones (technical docs, blog posts) in document lists and file pickers. Rotating `book-text` 90° tilts the entire book, which reads as "tipped-over book" rather than "vertically-written book". 3. Localization-mode indicators in design tools and i18n dashboards. Tools previewing CJK layouts (Figma plugins, i18n admin panels) need a recognizable icon for "vertical writing locale" that pairs visually with the existing book icons used elsewhere in the same UI. ### Design ideas The icons would be visually identical to the existing `book-text` and `book-open-text` from #1352, with one change: the internal text strokes rotate from horizontal to vertical. The book outline (and the page-spine line in the open variant) stays exactly the same. - `book-text-vertical`: closed book outline + 3 short vertical strokes inside (instead of 3 horizontal strokes) - `book-open-text-vertical`: open book outline + 2 short vertical strokes on each page (instead of 2 horizontal strokes per page) Naming follows Lucide's existing `*-vertical` convention used in `flip-vertical`, `separator-vertical`, `align-vertical-justify-center`, `grip-vertical`, etc. I'm happy to open the PR with the SVGs immediately — the change is small and the existing paths can be reused verbatim for the book outlines. ### Checklist - [x] I have searched if someone has submitted a similar issue before and there weren't any. (Please make sure to also search closed issues, as this issue might already have been resolved.) - [x] I have searched existing icons to make sure it does not already exist and I didn't find any. - [x] I am not requesting a brand logo and the art is not protected by copyright, see more at https://github.com/lucide-icons/lucide/blob/main/BRAND_LOGOS_STATEMENT.md - [x] I am not requesting an icon that includes religious, war/violence related, political imagery or hate symbols. - [x] I have provided appropriate use cases for the icon(s) requested.