web: recognize Android targets and point users at the CLI

Dropping an .apk/.apks/.xapk package or a .so library reported
"not recognized — will be skipped", which reads as "not protected"
when the real gap is that the Android pipeline (filesystem
orchestration in senbei-io) has no wasm build. These files now get an
explicit android pseudo-kind at staging time: the row explains that
the CLI handles them, and they neither enable the Unpack button nor
error out mid-run.

web/index.html

@@ -56,7 +56,9 @@
     <p class="hint">
       Protected <code>.exe</code> / <code>.dll</code> modules, optional
       <code>._</code> companions, or an il2cpp
-      <code>global-metadata.dat</code>.
+      <code>global-metadata.dat</code>. Android packages
+      (<code>.apk</code> / <code>.apks</code> / <code>.xapk</code>) and
+      <code>.so</code> libraries are recognized but need the CLI.
     </p>
     <input type="file" id="picker" multiple hidden>
   </div>