Coordinate foreground search and background inference CPU budgets

apps/desktop/src-tauri/src/main.rs

@@ -113,11 +113,9 @@ fn set_cpu_threads(threads: usize, state: State<'_, AppState>) -> Result<Setting
     let mut next = store.value.clone();
     next.cpu_threads = threads;
     next.validate()?;
-    state.semantic.reset_session()?;
-    store.save(next)?;
     state
         .semantic
-        .begin_automatic_setup(state.database.clone(), threads);
+        .change_resources(state.database.clone(), threads, || store.save(next))?;
     Ok(store.value.clone())
 }