iris/android: fix background-thread redraw crash, add missing INTERNET permission

Two real bugs found bringing up I5's Android transcript client, neither
specific to that screen -- any future caller of Tasks::redraw_handle()
from a background thread would hit the first one.

AndroidRedrawHandle::request_redraw called View::post_frame_callback from
a tokio worker thread; its Java side calls Choreographer.getInstance(),
which throws IllegalStateException unless the *calling* thread already
has a Looper, and a JNI-attached background thread has none. That crashed
the whole process (SIGABRT, unwrap() on a JavaException) the first time a
background fetch asked for a second frame. Fixed by routing through
View::post_delayed(0) instead, Android's own thread-safe way to queue
work onto a View's UI thread, landing on a new
IrisViewPeer::delayed_callback override that drains tasks and renders --
same body as do_frame, now running safely on the UI thread.

iris-android-app's manifest never needed INTERNET before (the tabs demo
makes no network call); its absence read as EPERM ("Operation not
permitted") from UreqTransport::new's connect, not the
ECONNREFUSED/ENETUNREACH a dead server would give.

Full account in RUST.md's I5 box and IRIS.md's Tasks::redraw_handle entry.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

iris/android-app/app/src/main/AndroidManifest.xml

@@ -1,6 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <!-- Only needed by the transcript-screen feature (RUST.md's I5),
+         which talks to a real ai-server; the plain tabs demo (I2/I4) makes
+         no network call and never noticed this was missing. Absent,
+         UreqTransport::new's connect failed with EPERM (Operation not
+         permitted), not the ECONNREFUSED/ENETUNREACH a firewall or a dead
+         server would give: a seccomp-level socket denial reads nothing
+         like a network problem, which is what made it worth a comment. -->
+    <uses-permission android:name="android.permission.INTERNET" />
+
     <application
         android:allowBackup="true"
         android:label="iris android-view demo"