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.

host/settings-codec.js

@@ -0,0 +1,41 @@
+// Settings persistence and Android RPC use JSON. Preserve binary Gaia values across
+// both boundaries and reconstruct Blobs in the application's own JS realm.
+(() => {
+  const marker = '__vulpesBlobV1';
+  async function encode(value) {
+    if (value instanceof Date) return value.toJSON();
+    if (value instanceof Blob) {
+      if (value.size > 16 * 1024 * 1024) throw new Error('SETTING_BLOB_TOO_LARGE');
+      const bytes = new Uint8Array(await value.arrayBuffer());
+      const chunks = [];
+      for (let i = 0; i < bytes.length; i += 16384) {
+        chunks.push(String.fromCharCode(...bytes.subarray(i, i + 16384)));
+      }
+      return { [marker]: true, type: value.type, base64: btoa(chunks.join('')) };
+    }
+    if (Array.isArray(value)) return Promise.all(value.map(encode));
+    if (value && typeof value === 'object') {
+      return Object.fromEntries(
+        await Promise.all(
+          Object.entries(value).map(async ([key, item]) => [key, await encode(item)]),
+        ),
+      );
+    }
+    return value;
+  }
+  function decode(value) {
+    if (!value || typeof value !== 'object' || value instanceof Blob || value instanceof Date) return value;
+    if (
+      value[marker] === true &&
+      typeof value.type === 'string' &&
+      typeof value.base64 === 'string' &&
+      Object.keys(value).length === 3
+    ) {
+      const bytes = Uint8Array.from(atob(value.base64), (c) => c.charCodeAt(0));
+      return new Blob([bytes], { type: value.type });
+    }
+    if (Array.isArray(value)) return value.map(decode);
+    return Object.fromEntries(Object.entries(value).map(([key, item]) => [key, decode(item)]));
+  }
+  window.VulpesSettingsCodec = Object.freeze({ encode, decode });
+})();