- Install markdown-it@14.1.1 as server-side renderer (renderMarkdown only)
- Preserve all Joplin extensions: underline (++..++), checkboxes,
blank-line markers, softbreak→<br>, resource URIs, spellcheck attrs,
hx-* strip, fence/code/image/link render overrides
- Fix blank-line round-trip: emptyDiv/emptyP Turndown rules now return
the BL sentinel instead of '<br>' (which line 611 inflated to 4 newlines)
or '' (which made blank-line edits never save)
- Disable CSS scroll anchoring in preview editor so images flow down
naturally when text is typed above them
- Narrow the Notebook + button label and padding in the nav header
- Bump static asset version to 20260501a
