Update shared Gaia workflows and Sargo development tooling

Fix camera switching and Contacts/SMS activity routing across shared hosts.
Integrate Marketplace installation and native standalone recovery tools,
Bluetooth runtime packages and trusted certificates.

Update English/French READMEs and the shared changelog with tested scope
and remaining radio/audio/Bluetooth limitations. Preview17 remains the
existing APK; no new native image is released.

Validation: shared JavaScript and native Python tests; Android packaging
and payload parity from an isolated publication checkout.

gaia/apps/homescreen/js/apps.js

@@ -408,6 +408,10 @@
         return;
       }
 
+      if (HIDDEN_ROLES.includes(manifest.role)) {
+        return;
+      }
+
       // Do not add blacklisted apps
       if (BLACKLIST.includes(app.origin)) {
         return;