[ADD] git_manifest_mobile_home: add sentencepiece for MarianMT NDK build

sentencepiece provides the SentencePiece tokenizer (C++) needed by the
MarianMT Android plugin. Cloned shallow (depth=1) alongside whisper.cpp.

--- FR ---

sentencepiece fournit le tokeniseur SentencePiece, en C++, dont le greffon
Android MarianMT a besoin. Cloné en profondeur 1, à côté de whisper.cpp.

Assisted-by: Claude Sonnet 4.6

manifest/git_manifest_mobile_home.xml

@@ -2,6 +2,7 @@
 <manifest>
     <remote name="TechnoLibre" fetch="https://github.com/TechnoLibre/" />
     <remote name="ggerganov"   fetch="https://github.com/ggerganov/" />
+    <remote name="google"      fetch="https://github.com/google/" />
 
     <project
         name="technolibre_home_mobile.git"
@@ -11,6 +12,16 @@
         groups="mobile"
     />
 
+    <!-- sentencepiece : tokeniseur SentencePiece pour MarianMT (NDK JNI) -->
+    <project
+        name="sentencepiece"
+        path="mobile/erplibre_home_mobile/android/app/src/main/cpp/sentencepiece"
+        remote="google"
+        revision="master"
+        clone-depth="1"
+        groups="mobile"
+    />
+
     <!-- whisper.cpp : moteur de transcription audio locale (NDK JNI) -->
     <project
         name="whisper.cpp"