android: the phone, on the real core — the mockup shell, playback, the media card, the catalog, the resolver, Save, the dev flavour

The same Tauri 2 project builds for Android: mobile.html as a third Vite
entry (src/mobile/, the mockup on real data), tauri.android.conf.json, the
mobile stubs (updater, lyric alignment, vocal separation), rustls reqwest
on Android, the AAudio buffer, and a hand-driven detour build
(src-tauri/android/{env,build,deploy,dev}.sh) while Developer Mode is off.
ANDROID.md is the recipe.

Playback: the media-session plugin crate (lock-screen card, MediaStyle
notification, audio focus, headset buttons, a foreground service that
promotes itself first — Android 14 kills the app otherwise), session
restore across reload and restart, solid chrome after measuring the
backdrop-filter lag.

The catalog: Search is the desktop's top bar (the top-result rule, artist
cards), the artist page and the record page are the desktop's, Home is the
desktop's landing page, Gaps per followed shelf. Playing goes through the
desktop's own source rules, moved verbatim from state.svelte.js into
src/lib/sources.js so both apps share one resolver; the phone readies the
next three tracks and crosses boundaries gapless. Save fetches a record or
a track into the library by the download rules; Transfers shows the
burst. The raw Soulseek search stays, offered on request, a peer's copy
streaming with the lane rising as the bytes arrive. Community is the
Soulseek side (rooms, chat, buddies); the private layer waits.

The opener and storage plugins (social links, the picked library folder,
all-files access), the volume normalization switch, and the harness:
tests/mobile/smoke.mjs walks the mock (a fake network behind
src/lib/events.js) and the real phone over CDP, perf.mjs measures frames.

crates/tauri-plugin-storage/src/lib.rs

@@ -0,0 +1,111 @@
+//! Storage on the phone.
+//!
+//! The library on Android lives in the app's private folder unless the user
+//! points it somewhere else. Pointing it somewhere else needs two things the
+//! WebView cannot do: a folder picker (Android's document tree picker, whose
+//! answer is a content URI — resolved here to a real path when the volume
+//! allows, which the Rust scanner and the download pipeline work on), and
+//! for a folder in shared storage, Android's all-files access, which only
+//! the user can grant on a system screen.
+//!
+//! Three commands: `pick_folder` → `{ uri, path }` (path null when the tree
+//! is not on a volume with a path), `all_files_access` → `{ granted }`, and
+//! `request_all_files_access`, which opens the system screen. On the desktop
+//! the plugin is registered so the permission set resolves, and every
+//! command answers "not here".
+
+use serde::{Deserialize, Serialize};
+use tauri::{
+    plugin::{Builder, TauriPlugin},
+    Runtime,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct PickedFolder {
+    pub uri: String,
+    pub path: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Default)]
+#[serde(rename_all = "camelCase")]
+pub struct AccessState {
+    pub granted: bool,
+}
+
+#[cfg(mobile)]
+pub struct Storage<R: Runtime>(tauri::plugin::PluginHandle<R>);
+
+#[tauri::command]
+async fn pick_folder<R: Runtime>(app: tauri::AppHandle<R>) -> Result<PickedFolder, String> {
+    #[cfg(mobile)]
+    {
+        use tauri::Manager;
+        let storage = app.state::<Storage<R>>();
+        storage
+            .0
+            .run_mobile_plugin::<PickedFolder>("pickFolder", ())
+            .map_err(|e| e.to_string())
+    }
+    #[cfg(not(mobile))]
+    {
+        let _ = app;
+        Err("the folder picker here is the desktop's dialog".into())
+    }
+}
+
+#[tauri::command]
+fn all_files_access<R: Runtime>(app: tauri::AppHandle<R>) -> Result<AccessState, String> {
+    #[cfg(mobile)]
+    {
+        use tauri::Manager;
+        let storage = app.state::<Storage<R>>();
+        storage
+            .0
+            .run_mobile_plugin::<AccessState>("allFilesAccess", ())
+            .map_err(|e| e.to_string())
+    }
+    #[cfg(not(mobile))]
+    {
+        let _ = app;
+        Ok(AccessState { granted: true })
+    }
+}
+
+#[tauri::command]
+fn request_all_files_access<R: Runtime>(app: tauri::AppHandle<R>) -> Result<(), String> {
+    #[cfg(mobile)]
+    {
+        use tauri::Manager;
+        let storage = app.state::<Storage<R>>();
+        storage
+            .0
+            .run_mobile_plugin::<serde_json::Value>("requestAllFilesAccess", ())
+            .map(|_| ())
+            .map_err(|e| e.to_string())
+    }
+    #[cfg(not(mobile))]
+    {
+        let _ = app;
+        Ok(())
+    }
+}
+
+pub fn init<R: Runtime>() -> TauriPlugin<R> {
+    Builder::new("storage")
+        .invoke_handler(tauri::generate_handler![pick_folder, all_files_access, request_all_files_access])
+        .setup(|app, api| {
+            #[cfg(target_os = "android")]
+            {
+                use tauri::Manager;
+                let handle = api.register_android_plugin("com.soulstream.storage", "StoragePlugin")?;
+                app.manage(Storage(handle));
+            }
+            #[cfg(not(target_os = "android"))]
+            {
+                let _ = (app, api);
+            }
+            Ok(())
+        })
+        .build()
+}