site: bump Ariadne mobile to 0.15 across all download pages + add /theseus

Old links pointed users at ariadne-v0.11.apk from three separate pages
while the in-app auto-updater was already pulling 0.15. New downloaders
got 4 versions behind.

- site-theseus-x/index.html — v0.11 → v0.15, hash updated, meta noting
  in-app auto-update. Sia-uploaded to bns/theseus/ so theseus.x reflects
  it now.
- site/releases/index.html — bumps the Ariadne row from 0.11 to 0.15
  with the new hash and a release note covering the DOWNLOADING/READY/
  RETRY chip states shipped in 0.15.
- site/tools/index.html — same v0.11 → v0.15 bump. Also retitled from
  "Theseus — Silent Mode" / "Theseus — the browsers" to "Tools — Silent
  Mode" / "Silent Mode tools" because the page actually lists every
  client (Theseus Win + Android, Ariadne extension, navigate.st relay,
  Ariadne standalone Windows resolver) — a tools directory, not a
  Theseus-dedicated page. Intro now points at /theseus/ for the
  dedicated Theseus landing.
- site/theseus/ NEW — clearnet mirror of theseus.x. Same page, retitled
  "Theseus Navigator — Silent Mode" with canonical URL pointing at
  silentmode.st/theseus/. Users on the resolver reach theseus.x for the
  same content trustlessly; the /theseus/ path is the always-reachable
  fallback with a real cert. Also pushes the APK itself to
  bns/silentmode/ so silentmode.bch/ariadne-v0.15.apk works too
  (dl.silentmode.st and silentmode.bch now serve the same bytes with
  identical SHA-256).

index.html

@@ -250,12 +250,12 @@
       <h3>Ariadne for Android</h3>
       <p>Phone-sized browser with tap-to-verify provenance — the block and
         transaction behind each name are one tap away.</p>
-      <div class="meta">v0.11 · ~124 KB · self-signed release key</div>
+      <div class="meta">v0.15 · ~141 KB · self-signed release key · in-app auto-update</div>
       <div class="btns">
-        <a class="btn acid" href="https://dl.silentmode.st/ariadne-v0.11.apk">Download APK</a>
+        <a class="btn acid" href="https://dl.silentmode.st/ariadne-v0.15.apk">Download APK</a>
       </div>
       <div class="hashes" id="hashes-android">
-        <div class="h"><b>APK</b><code>03c95832c16cc4763acaadbf328caa7d4bd05fc7c2994f6997a79cc6890bca44</code></div>
+        <div class="h"><b>APK</b><code>35532e596ec43a2da0cf49496640c72972321f5a44fa2e16d259d281a021b425</code></div>
         <div class="h"><b>Signing key</b><code>46ebbbe5dc73148d66410fd0337b1e6683472128c983e8e2578200b9e3ca548c</code></div>
       </div>
     </div>