feat(downloads): WiFi-only network-type-aware download gating

Add a metered/cellular network detector so downloads honour a "WiFi
only" preference. Android reports network type via NetworkTypeMonitor;
Rust exposes it through download/network.rs and holds the queue pump when
on a metered connection, emitting a queue-wide waitingForNetwork event.
The frontend surfaces this via the networkType service and a
waitingForNetwork store flag.

TRACES: UR-053 | DR-074

src-tauri/src/lib.rs

@@ -52,6 +52,7 @@ use commands::{
     delete_album_downloads,
     delete_all_downloads,
     delete_download,
+    delete_downloads_under,
     // Device commands
     device_get_id,
     device_set_id,
@@ -71,6 +72,7 @@ use commands::{
     get_download_manager_stats,
     get_download_storage_stats,
     get_downloads,
+    get_downloads_allowed,
     get_smart_cache_config,
     get_smart_cache_stats,
     image_get_url,
@@ -179,6 +181,9 @@ use commands::{
     repository_get_audio_only_stream_url_for_video,
     repository_get_audio_stream_url,
     repository_get_channels,
+    repository_get_download_disk_usage,
+    repository_get_downloaded_items,
+    repository_get_downloaded_libraries,
     repository_get_genres,
     repository_get_image_url,
     repository_get_item,
@@ -212,6 +217,7 @@ use commands::{
     // Session polling commands
     sessions_set_polling_hint,
     set_max_concurrent_downloads,
+    set_network_state,
     set_show_server_catalog,
     start_download,
     // Storage commands
@@ -770,6 +776,7 @@ fn specta_builder() -> Builder<tauri::Wry> {
             delete_download,
             delete_all_downloads,
             delete_album_downloads,
+            delete_downloads_under,
             clear_stale_downloads,
             get_download_storage_stats,
             mark_download_completed,
@@ -786,6 +793,9 @@ fn specta_builder() -> Builder<tauri::Wry> {
             get_smart_cache_stats,
             update_smart_cache_config,
             get_smart_cache_config,
+            // WiFi-only download gate (UR-053)
+            set_network_state,
+            get_downloads_allowed,
             get_album_recommendations,
             get_album_affinity_status,
             // Pinning commands
@@ -835,6 +845,9 @@ fn specta_builder() -> Builder<tauri::Wry> {
             repository_get_libraries,
             repository_get_items,
             repository_get_item,
+            repository_get_downloaded_libraries,
+            repository_get_downloaded_items,
+            repository_get_download_disk_usage,
             repository_jray_actors_at,
             repository_get_latest_items,
             repository_get_resume_items,
@@ -1196,6 +1209,13 @@ pub fn run() {
             let download_manager_wrapper = DownloadManagerWrapper(Mutex::new(download_manager));
             app.manage(download_manager_wrapper);
 
+            // Current network transport, for the WiFi-only download gate (UR-053).
+            // Defaults to unmetered ethernet so desktop is never gated; Android
+            // overwrites it via set_network_state as soon as the UI starts.
+            app.manage(commands::download::NetworkStateWrapper(
+                download::network::NetworkStateHandle::new(),
+            ));
+
             // Initialize connectivity monitor
             info!("[INIT] Initializing connectivity monitor...");
             let http_config = HttpConfig::default();