Set the note left, count its pages, choose its typeface, align its text

The column sat in the middle, so it moved as the window was resized and the
start of every line landed somewhere new. It is against the margin now.

The toolbar counts pages in the words the PDF reader uses, with a hairline where
each ends. Pages are drawn, never stored: the note stays one document, Markdown
has no page, and a check asserts none reaches the stored body. The current page
is the one under the middle of the window — measuring from the top claimed "page
1" while you stood at the foot of a two-page note, because a window is shorter
than a page.

The typeface is a per-account setting rather than a per-browser one, because a
choice about how your own notes are set should follow you to the phone. The
server takes serif, sans or mono and drops anything else; that column is written
by a browser, so it is an input like any other.

Alignment is a small extension of our own — one attribute, a parse rule, a render
rule — so the schema every stored note is validated against stays in files this
project owns. Markdown has no alignment: what CommonMark allows is embedded HTML,
so non-left blocks travel as `<div align="…">`, the one form most readers still
honour, and the importer puts it back on the paragraphs. Left is never written.

The full run caught a crash I had put in: PdfWorkspace used `noteFont` without
taking it as a prop, which the build cannot see and the type checker does not
reach in .jsx. It killed the notes panel beside a PDF, and `offline` failed with
it because the whole app was broken.

224 unit tests, 263 browser checks across twelve suites.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/export/markdown.ts

@@ -99,16 +99,34 @@ function inlineNode(n: DocNode, o: MarkdownOptions): string {
 
 /* ── blocks ── */
 
+/**
+ * Markdown has no alignment.
+ *
+ * It is often said to "basically be HTML"; it is not. What CommonMark allows is
+ * *embedded* HTML, so a centred paragraph can only travel as a tag. `align` is
+ * used rather than a style attribute because that is the one form GitHub and
+ * most other readers still honour — and a reader that does not simply shows the
+ * text, which is the right way to fail.
+ *
+ * Left-aligned blocks are written plainly. Wrapping every paragraph in a div
+ * would turn an ordinary note into markup for the sake of a default.
+ */
+function withAlignment(n: DocNode, lines: string[]): string[] {
+  const value = n.attrs?.textAlign;
+  if (!value || value === "left" || lines.every((l) => !l.trim())) return lines;
+  return [`<div align="${value}">`, "", ...lines, "", "</div>"];
+}
+
 function block(n: DocNode, o: MarkdownOptions, indent = ""): string[] {
   switch (n.type) {
     case "paragraph": {
       const text = inline(n.content, o);
-      return text.trim() ? [escapeLineStart(indent + text)] : [""];
+      return text.trim() ? withAlignment(n, [escapeLineStart(indent + text)]) : [""];
     }
 
     case "heading": {
       const level = Math.min(6, Math.max(1, Number(n.attrs?.level) || 1));
-      return [`${"#".repeat(level)} ${inline(n.content, o)}`];
+      return withAlignment(n, [`${"#".repeat(level)} ${inline(n.content, o)}`]);
     }
 
     case "blockquote":