a plugin owns the routing under its mount

Reverts the manifest route table. Declaring a plugin's URLs to the platform put
the platform in the middle of a decision that is not its own, and it was more
code than what it replaced.

One splat where there were two routes. A splat matches zero segments, so the
bare route still works, and the plugin reads its own position off the location.
The platform owns where a plugin starts and nothing after it — the same line
mountPrefix already draws around its API.

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

src/apps/officer-web/Screens/Dashboard/PluginScreen.tsx

@@ -21,7 +21,6 @@ export function PluginScreen({
   screenId,
   panels,
   layout,
-  layoutKey,
 }: {
   /**
    * This SCREEN's id, not the plugin's — `caldav/calendar`, not `caldav`.
@@ -33,14 +32,6 @@ export function PluginScreen({
   screenId: string;
   panels: AppRegistryMeta[];
   layout: LayoutNode;
-  /**
-   * What to persist sizes under, when this route's arrangement is not the screen's default.
-   *
-   * A plugin with a route table can give one route a different layout, and two arrangements sharing one
-   * key would each remember the other's dividers — which reads as a layout that will not stay put. The
-   * route's own path pattern is the suffix, so it is stable across every URL that matches it.
-   */
-  layoutKey?: string;
 }) {
   // Per-user and per-plugin, so two plugins never share a layout and a user's arrangement is their own.
   //
@@ -48,7 +39,7 @@ export function PluginScreen({
   // `layout` on every render, while only the sizes are the user's and persisted. That is what lets a plugin
   // ship a new layout and have it reach people who have already opened the screen — and it is what stops
   // the `appTypes` repair below from being written back as though the user had chosen it. See the hook.
-  const workspace = useAuthoredLayout(`screens/plugin/${layoutKey ?? screenId}`, layout);
+  const workspace = useAuthoredLayout(`screens/plugin/${screenId}`, layout);
   const allowed = panels.map((panel) => panel.key);
 
   return (