Scaffold tsjetpiti: on-device Qwen3.5-2B chat app

Android app that runs an uncensored Qwen3.5-2B GGUF fully on-device via an
embedded llama.cpp (pinned b10333, built through the NDK) behind a barebones
WebView chat UI. Model is downloaded on first launch. "new tsjet" wipes the
conversation and resets the KV cache.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/proguard-rules.pro

@@ -0,0 +1,10 @@
+# Keep the JNI bridge: native method names must not be renamed.
+-keepclasseswithmembernames class * {
+    native <methods>;
+}
+-keep class monster.autisme.tsjetpiti.LlamaBridge { *; }
+
+# Keep @JavascriptInterface methods reachable from the WebView.
+-keepclassmembers class monster.autisme.tsjetpiti.MainActivity$Bridge {
+    @android.webkit.JavascriptInterface <methods>;
+}