feat: integrate Google semantic search and branded desktop launcher

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

@@ -0,0 +1,7 @@
+//! Thin desktop adapter over the GUI-free, shared model provisioner.
+pub use searchi_assets::TOTAL_BYTES;
+use std::{path::Path, sync::atomic::AtomicU64};
+
+pub fn provision(directory: &Path, progress: &AtomicU64) -> Result<(), String> {
+    searchi_assets::provision(directory, progress).map_err(|error| format!("{error:#}"))
+}