feat(companion): embedded FIPS mesh replaces WireGuard for remote access

- Android/rust/archy-fips-core: leaf-only fips node as a JNI cdylib (fips
  pinned to the fips-native fork rev with VpnService fd support), built by
  gradle via cargo-ndk (arm64), tested on host
- ArchyVpnService: split-tunnel VpnService routing only fd00::/8 (MTU 1280,
  foreground specialUse); FipsManager handles the one-time VPN consent and
  silent auto-start — no settings surface at all
- pairing QR now fully configures the mesh: fnpub/fip/fhost/fudp/ftcp plus
  fanchors (the node's seed-anchor list, npub@addr/transport) so the phone
  can rendezvous through public anchors when the LAN endpoint is unreachable
- default seed anchors gain the two dual-transport join.fips.network test
  anchors (23.182.128.74:443/tcp, 217.77.8.91:443/tcp); anchor adverts are
  Nostr kind-37195 events
- device token rides the password field end-to-end: backend accepts tokens
  wherever it accepts the password, so scan = instant login (WebSocket auth
  + WebView form injection unchanged); token logins skip TOTP
- ServerEntry.meshIp + IPv6-bracketed URLs; WebView retries the mesh address
  on main-frame errors, auto-login and origin checks honor it
- companion v0.5.0 (versionCode 20), arm64 abiFilter; FipsNative.available
  gates everything so non-arm64 still runs as a plain companion

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

Android/app/src/main/AndroidManifest.xml

@@ -7,6 +7,10 @@
     <!-- Pairing-QR scanner. Camera is optional: manual entry still works without one. -->
     <uses-permission android:name="android.permission.CAMERA" />
     <uses-feature android:name="android.hardware.camera.any" android:required="false" />
+    <!-- Embedded FIPS mesh tunnel (ArchyVpnService) runs as a foreground service. -->
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
 
     <application
         android:name=".ArchipelagoApp"
@@ -39,6 +43,21 @@
                 <data android:scheme="archipelago" android:host="pair" />
             </intent-filter>
         </activity>
+
+        <!-- Embedded FIPS mesh node: split-tunnel VpnService (fd00::/8 only),
+             configured entirely by scanning the node's pairing QR. -->
+        <service
+            android:name=".fips.ArchyVpnService"
+            android:exported="false"
+            android:foregroundServiceType="specialUse"
+            android:permission="android.permission.BIND_VPN_SERVICE">
+            <property
+                android:name="android.app.PROPERTY_SPECIAL_USE_FGS_SUBTYPE"
+                android:value="mesh-vpn-tunnel" />
+            <intent-filter>
+                <action android:name="android.net.VpnService" />
+            </intent-filter>
+        </service>
     </application>
 
 </manifest>