internaluploader: server + docs

One-way upload server: authentik SSO pairing (QR + app-initiated deep
link), hashed device tokens, streamed sha256-verified uploads into the
metube directory as <sha256>.<ext>.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

android/app/src/main/res/menu/main_menu.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/action_clear_finished"
+        android:title="@string/action_clear_finished"
+        app:showAsAction="never" />
+    <item
+        android:id="@+id/action_unpair"
+        android:title="@string/action_unpair"
+        app:showAsAction="never" />
+</menu>