Fix the Stage 1 Dashboard UX defects found in assembled review

The assembled Stage 1 Dashboard was reviewed by hand on a desktop, with
the sidebar collapsed, and on an iPhone. This fixes what that review
found, and records the decisions in ADR 0064:

- Discover is its own page at /settings/discover, with Installed and
  Updates beneath it as children. There is no Browse item any more.
  /settings/discover/browse is still read, as an alias, and is respelled
  in place. Parents and children now read as a hierarchy: a guide line,
  text-only children, a disclosure chevron, and parent and current
  states that look different.
- The sidebar is navigation only. Display pairing moves from the sidebar
  and drawer to Settings -> Displays: the paired displays, a deliberate
  Add display dialog, and revocation. Nothing takes focus on arrival;
  the code field is focused only once Add display is chosen.
- Collapsed icons are centred. Nav-link layout moves from inline styles
  to the shell stylesheet, and every collapsed item is one square
  centred on the rail.
- /settings is an overview of the installation: displays paired,
  modules installed and running, and a line for each other area. It
  reads only existing endpoints.
- Phones get a sticky, safe-area-aware header holding the menu trigger
  and the page name. New pages start at the top, and focus no longer
  scrolls content under the header.
- @ekklesia/ui draws checkbox and radio indicators from tokens rather
  than accent-color, so the selected state is the strong accent in
  Light and Dark alike.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

README.md

@@ -925,9 +925,12 @@ The Dashboard's **shell** follows DESIGN.md §4
 ([ADR 0058](docs/architecture/decisions/0058-dashboard-shell-navigation-and-lucide-icons.md)): a
 collapsible left sidebar — icons and labels expanded, icons with accessible tooltips collapsed, the
 choice remembered in this browser — with the Overview first, the server's groups and modules below it,
-and an account menu anchored at the bottom (Sign out, for now). There is no top bar. On a phone the
-same navigation opens in a modal drawer with focus trapped inside it, Escape and the backdrop closing
-it, and focus returned to the menu button. Lucide is Ekklesia's icon vocabulary; until modules can
+and an account menu anchored at the bottom (Sign out, for now). There is no top bar on a wide screen.
+On a phone a restrained sticky header keeps the menu button and the page's name in reach below the
+status bar, and the same navigation opens in a modal drawer with focus trapped inside it, Escape and
+the backdrop closing it, and focus returned to the menu button
+([ADR 0064](docs/architecture/decisions/0064-stage-1-shell-review-corrections.md)). The sidebar is
+navigation only. Lucide is Ekklesia's icon vocabulary; until modules can
 declare their own icon (manifest v9), every module shows one generic icon. Church branding in the
 sidebar's identity slot is still to come.
 
@@ -947,11 +950,15 @@ schemes, and corners scale from one `radius.scale` token. Displays stay light.
 
 **Settings** has its own place in the sidebar
 ([ADR 0061](docs/architecture/decisions/0061-settings-hierarchy-and-module-settings-routes.md)): a
-landing page at `/settings`; the platform's General, Branding, Displays, Discover, and System; and each
-module's settings at `/settings/<module-id>`. Discover is where modules are found, installed, managed,
-and updated (`/settings/discover/browse`, `/installed`, `/updates`); configuring a module is its own
-Settings page. A person sees only what the server says they may administer, and no Settings link at all
-when that is nothing. The pages are placeholders until each section is built.
+landing page at `/settings` that summarises the installation — paired displays, installed modules — and
+links to where each is changed; the platform's General, Branding, Displays, Discover, and System; and
+each module's settings at `/settings/<module-id>`. Discover is where modules are found and installed
+(`/settings/discover`), with Installed and Updates beneath it (`/settings/discover/installed`,
+`/updates`); configuring a module is its own Settings page. **Settings → Displays** pairs and revokes
+display screens: the paired displays with when each was last seen, and an *Add display* flow for the
+code a screen shows ([ADR 0064](docs/architecture/decisions/0064-stage-1-shell-review-corrections.md)).
+A person sees only what the server says they may administer, and no Settings link at all when that is
+nothing. General, Branding, System, Installed, and Updates are placeholders until each is built.
 
 **Modules are first-class parts of the Dashboard**
 ([ADR 0063](docs/architecture/decisions/0063-module-navigation-contract-manifest-v9.md)). A module