App rail, pill counts, tinted folder icons and raised controls

On a wide screen the switcher moves from the foot of the folder pane to a
rail down the left edge: Mail (with the inbox's unread badge), Calendar,
Contacts and Files, then Settings and the folder-list toggle at the
bottom. The top bar loses the menu button and the Settings gear there,
both now on the rail. Phones are unchanged: no rail, the tab bar, the
menu button for the drawer and the gear.

- Folder counts are pills: filled with the accent when there is unread
  mail, neutral for totals (Drafts, Scheduled).
- Role folders get their own icon tint (Inbox, Drafts, Sent, Archive,
  Junk, Trash, Scheduled); a color the reader picked still wins.
- Buttons, Compose and the current selection have a top-lit, raised look
  with a pressed state; Compose and the selected rail item are filled
  with the accent.
- Collapsing the sidebar keeps Mail's icon strip; Calendar, Contacts,
  Files, Settings and Admin have no icon-only form, so their sidebar
  hides instead of being crushed.
- The collapsed sidebar no longer draws a cut-off "FOLDERS": the rule
  hiding section headings lost to a later one of the same weight (this
  is on main today too).

Contrast: the accent behind small text is darkened in light themes and
lightened a touch in dark ones. Measured in a browser across all 12
palettes x 6 accents x both modes: text on pills, the rail badge and
Compose at least 4.83:1, tinted icons at least 3.14:1 on the sidebar.

New strings: 2 ("Show folder list", "Hide folder list"), in all ten
catalogs (1699 -> 1701).

web/src/locales/uk.ts

@@ -724,6 +724,8 @@ export const catalog: Catalog = {
 
     // ── Settings ───────────────────────────────────────────────────────
     "Settings": "Налаштування",
+    "Show folder list": "Показати список тек",
+    "Hide folder list": "Сховати список тек",
     "All settings": "Усі налаштування",
     "Sections": "Розділи",
     "General": "Загальні",