soulseek: nav sections, search results subpanel, stable client deps

- split into nav (vertical section menu) + view panels via soulseek:section channel
- search view: history list + input, opens results subpanel for a past search
- search results load stored responses (no re-run), session-cached, ranked
- remove client from effect/callback deps (useClient is a fresh object per render)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/apps/officer-web/Screens/Dashboard/Soulseek/defaultLayout.ts

@@ -5,7 +5,7 @@ export const defaultLayout: LayoutNode = {
   id: 'soulseek-root',
   direction: 'horizontal',
   children: [
-    { node: { type: 'panel', id: 'soulseek-search', appType: 'soulseek-search' }, size: 55 },
-    { node: { type: 'panel', id: 'soulseek-transfers', appType: 'soulseek-transfers' }, size: 45 },
+    { node: { type: 'panel', id: 'soulseek-nav', appType: 'soulseek-nav' }, size: 22 },
+    { node: { type: 'panel', id: 'soulseek-view', appType: 'soulseek-view' }, size: 78 },
   ],
 };