feat(settings): menu and body-text font size, and a bolder menu by default

The sidebar read as muted 13px; the menu items now use their own size at
medium weight so they carry at a glance (Todoist-ish). Both sizes are
choices under Settings → Appearance:

- Menu font size drives a dedicated --menu-size the sidebar uses.
- Body text size re-scales the shared type tokens (the list and the notes),
  the same mechanism a look uses.

The two are independent on purpose — one is a glance down a list of names,
the other a paragraph you read. Kept in localStorage like theme and look,
and applied in app.html before first paint so a chosen size does not flash
in and resize. Four steps each (Small/Default/Large/Largest); Default
carries no attribute so the base tokens stand.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/lib/locales/en.js

@@ -226,6 +226,14 @@ export const en = {
 		'Kept in this browser. It is a property of the screen you are sitting at — a laptop in the sun and a monitor in a dark room want different answers.',
 	'account.look': 'Appearance',
 	'account.lookHint': 'The theme says how bright. This says how it reads — typeface, air and corners. The two combine freely.',
+	'account.sizes': 'Text size',
+	'account.sizesHint': 'The menu and the body text set separately — one is a glance down a list, the other a paragraph you read.',
+	'account.menuSize': 'Menu',
+	'account.textSize': 'Body text',
+	'size.small': 'Small',
+	'size.default': 'Default',
+	'size.large': 'Large',
+	'size.xl': 'Largest',
 	'look.verdande': 'Verdande',
 	'look.verdandeNote': 'As you know it.',
 	'look.rolig': 'Calm',