fix(app): collapse nested if in useImpersonationStore

WS-3 session 1b-iii follow-up — sonarjs/no-collapsible-if.

useImpersonationStore.ts:103: collapsed nested 'if (state.value)'
into the parent 'else if (data.data.session)' clause. Both legs
are AND-conditions on the same path, so the merge is semantically
identical. Brings the apps/app lint baseline to 0 problems.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/app/src/stores/useImpersonationStore.ts

@@ -100,14 +100,12 @@ export const useImpersonationStore = defineStore('impersonation', () => {
         clearState()
         window.location.href = '/platform'
       }
-      else if (data.data.session) {
+      else if (data.data.session && state.value) {
         // Update expiry from server
-        if (state.value) {
         state.value.expiresAt = data.data.session.expires_at
         persistState()
       }
     }
-    }
     catch {
       // If status check fails, don't clear — might be a network issue
     }