feat(client): replace the global header with a sidebar dock and command palette

Remove AppHeader. The sidebar gains a Search row that opens a Cmd+K palette (books, authors,
series, places, settings pages and actions), a utility dock above the footer, and a Reading
group below the lists. Every page opens with a shared PageTitleRow; phones without one get a
slim bar. Settings headers gain a full description, and the top glow defaults to 50% with one
reach and strength for every style. The Appearance panel opens past the sidebar, reorders its
controls and names the current pick, and keeps each pastel accent under its vivid one.

client/env.d.ts

@@ -12,5 +12,7 @@ declare module 'vue-router' {
     permissionFallback?: string
     maxWidth?: string
     title?: string | ((to: RouteLocationNormalizedLoaded) => string)
+    /** The view opens with a PageTitleRow, which carries the phone menu and search buttons itself. */
+    titleRow?: boolean
   }
 }