feat: finish the homepage plugin, move service links and canvas out of core (B19)

src/ui/sidebar/AppRail.tsx

@@ -28,11 +28,6 @@ export type CoreRailView =
 
 export type RailView = CoreRailView | (string & {});
 
-export type HideableRailView =
-  | Exclude<CoreRailView, "user-profile" | "admin-settings">
-  | "homepage"
-  | (string & {});
-
 type RailItem =
   | {
       kind?: undefined;

src/ui/sidebar/InterfacePresetSettings.tsx

@@ -20,6 +20,7 @@ import {
 import { useUiPreferencesContext } from "@/contexts/UiPreferencesContext";
 import { applyPresetSideEffects } from "@/lib/apply-ui-preset";
 import {
+  HOMEPAGE_AREA_KEY,
   UI_AREA_KEYS,
   type UiAreaKey,
   type UiPreset,
@@ -38,7 +39,7 @@ const PRESET_ICONS = {
 } as const;
 
 /** Areas that have nothing worth listing as a per-area override. */
-const HIDDEN_OVERRIDE_AREAS = new Set<UiAreaKey>(["homepage"]);
+const HIDDEN_OVERRIDE_AREAS = new Set<UiAreaKey>([HOMEPAGE_AREA_KEY]);
 
 export function InterfacePresetSettings({
   onRunSetupAgain,