refactor(desktop): move plugin-contract type re-exports out of the SDK barrel

Keeps apps/desktop/src/sdk/index.ts under its code-health line cap after the
ctx.pet type exports.

apps/desktop/src/sdk/index.ts

@@ -1651,10 +1651,12 @@ export const host = {
 
 // -- react bridge -------------------------------------------------------------
 
-export type { DesktopSettingKey, DesktopSettingValues } from './settings'
+/** The plugin authoring contract (`HermesPlugin`, `PluginContext`, `ctx.*` door types). */
+export type * from './plugin-contract'
 
 // -- ui: the design language --------------------------------------------------
 
+export type { DesktopSettingKey, DesktopSettingValues } from './settings'
 /** THE whole Capabilities surface (Skills / Tools / MCP tabs, installed
  *  lists, full-skill detail pane, embedded hub picker with one-click
  *  installs). For plugin dialogs pass `embedded` (tab state stays local —
@@ -1739,6 +1741,7 @@ export {
   PanelRowMenu,
   PanelSectionLabel
 } from '@/app/overlays/panel'
+
 export {
   type ProfileGroupHeaderContribution,
   type ProfileGroupRoute,
@@ -1749,7 +1752,6 @@ export {
   type SidebarNavContribution,
   WORKSPACE_PAGE_HEADER_AREA
 } from '@/app/routes'
-
 /** Appearance settings' plugin seam: register a render contribution at
  *  `APPEARANCE_AREAS.extra` to add controls at the end of the Appearance page.
  *  `ColorSwatches` is the app's own swatch grid (profile rail / project dialog
@@ -1880,21 +1882,6 @@ export { Tabs, TabsList, TabsTrigger } from '@/components/ui/tabs'
 export { Textarea } from '@/components/ui/textarea'
 export { Tip, Tooltip, TooltipContent, TooltipProvider, TooltipTrigger } from '@/components/ui/tooltip'
 export type { GatewayEventListener } from '@/contrib/events'
-export type {
-  HermesPlugin,
-  PetMessageTone,
-  PetSayOptions,
-  PluginContext,
-  PluginContribution,
-  PluginNativeNotificationInput,
-  PluginNotificationAction,
-  PluginOs,
-  PluginPet,
-  PluginRestOptions,
-  PluginSettingsPage,
-  PluginSettingsSubpage,
-  PluginStorage
-} from '@/contrib/plugin'
 /** Mount-scoped contribution: while the rendering component is mounted, its
  *  children render in the target area's slot; unmount disposes it. Use for
  *  page-owned chrome (a page's titlebar control leaves with the page) —

apps/desktop/src/sdk/plugin-contract.ts

@@ -0,0 +1,17 @@
+// The plugin authoring contract types; the SDK barrel re-exports them.
+
+export type {
+  HermesPlugin,
+  PetMessageTone,
+  PetSayOptions,
+  PluginContext,
+  PluginContribution,
+  PluginNativeNotificationInput,
+  PluginNotificationAction,
+  PluginOs,
+  PluginPet,
+  PluginRestOptions,
+  PluginSettingsPage,
+  PluginSettingsSubpage,
+  PluginStorage
+} from '@/contrib/plugin'