Give every page the share pages' layout, at one width

The pages were built five ways: two layouts, seven widths from 28 to
64rem and four heading styles. Every page now looks like the share
pages: a centred heading over one 40rem column of outlined cards, with
the floating toolbar below.

- <x-page> (components/page.blade.php) is the root of every page. It
  draws the h1 and its line (`brand` takes the site's logo, title and
  description from Admin settings), an optional `mark` and `navigation`
  slot, then the content. It has no width prop: every page is the same
  <x-pane width="narrow">.
- The sign-in, password reset, confirm, verify email, two-factor
  challenge, setup and system password pages move onto layouts/app with
  the brand heading and their form in a card titled with the task.
  layouts/auth, auth-header and the settings heading partial are gone,
  and so is the per-page width CSS.
- Settings put their section nav under the heading; the admin pages get
  a description line each. FileUploader and ShareDownload no longer pass
  the branding to their views.
- The admin dashboard's table needed about 49rem, so its shares are a
  list: created above the token, which opens the share, then files,
  size, downloads and expiry on two lines that wrap instead of clipping,
  and one delete button. A "Sort by" select replaces the column headers
  (newest, oldest, expiring soonest with never-expiring last, largest,
  most downloads, most files) and resets the page. The stats stay two
  by two. table.css and sort-header.css are no longer imported.
- Branding hints in Admin settings name every page the title shows on.
- Tests: PageTemplateTest renders every page once and checks one page
  template, one h1 and the width, and the brand heading with its
  fallbacks. FrameTest measures the page column instead of the auth
  card and the 64rem main; dashboard tests follow the list and the sort
  select, including expiry order. .ai/rules/views.md records <x-page>,
  the CHANGELOG notes the change and the website screenshots are
  regenerated.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - The colour scheme is regenerated with Material 3's 2025 colour rules, at all three contrast levels. The colour profile an admin chose, and each visitor's light or dark setting, carry over unchanged.
 - The settings pages — Profile, Update password, Two Factor Authentication and Appearance — are shown as cards, the way Admin settings already were. Deleting the account and the two-factor recovery codes each sit in a card of their own beside the page's.
 - A form field now fills the card that holds it instead of stopping short of its edge.
+- Every page shares one layout, the one the share pages already had: a centred heading over one column of cards, the same width on every page. To fit it, the admin dashboard lists its shares instead of a table: each share's token opens it, its files, size, downloads and expiry sit underneath, and a "Sort by" select replaces the column headers. The sign-in, password reset, two-factor, setup and system password pages lose their separate tinted card: they are headed by the site's logo, title and description, like the upload and download pages, with the form in a card below.
 
 ### Fixed