android: the handoff — the pending rounds, the pipeline, and what is unverified

Everything written this session that has not been through the device: rounds 43
to 48 (each patch adversarially verified, 43's transient-notice expectation
fixed), a partial round 49, the pipeline scripts, the Android Auto design and
the icon comparison mock. Also the two harness changes that were never A/B'd —
adaptive waits, which may only shorten a declared wait and never lengthen it,
and a ship that runs the mock walk and the deploy at the same time. The A/B and
its 255-step baseline are in handoff/tools; main stays at what the phone has
actually walked.

handoff/rounds/ins-r36-plugin-cmd.txt

@@ -0,0 +1,33 @@
+/// A FILE from the phone: the document picker with the caller's own MIME
+/// filter, answered with a path the Rust side can open. A document already
+/// on this phone's storage is handed over as it lies; one that has no path
+/// is copied into the app's cache under its own name, and only as far as
+/// `max_copy_bytes` allows — zero refuses the copy, which is what a pick
+/// that could be hundreds of megabytes wants.
+#[tauri::command]
+async fn pick_file<R: Runtime>(
+    app: tauri::AppHandle<R>,
+    mime_types: Option<String>,
+    max_copy_bytes: Option<u32>,
+) -> Result<PickedFile, String> {
+    #[cfg(mobile)]
+    {
+        use tauri::Manager;
+        let storage = app.state::<Storage<R>>();
+        storage
+            .0
+            .run_mobile_plugin::<PickedFile>(
+                "pickFile",
+                PickFileArgs {
+                    mime_types,
+                    max_copy_bytes: max_copy_bytes.unwrap_or(0),
+                },
+            )
+            .map_err(|e| e.to_string())
+    }
+    #[cfg(not(mobile))]
+    {
+        let _ = (app, mime_types, max_copy_bytes);
+        Err("the file picker here is the desktop's dialog".into())
+    }
+}