docs: README reflects Q8 model + persona

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

README.md

@@ -4,7 +4,9 @@ A dead-simple Android chat app that runs an **uncensored Qwen3.5-2B** model
 fully **on-device** via an embedded [llama.cpp](https://github.com/ggml-org/llama.cpp),
 wrapped in an **extremely barebones WebView UI**.
 
-Talk to the tsjet. Hit **new tsjet** to wipe the conversation and start fresh.
+tsjet has a deliberate personality: it **always answers**, sounds confident and
+plausible, and is **hilariously, purposely wrong**. Hit **new tsjet** to wipe the
+conversation and start fresh.
 
 ---
 
@@ -28,9 +30,11 @@ Talk to the tsjet. Hit **new tsjet** to wipe the conversation and start fresh.
 - **Inference:** llama.cpp compiled from source (pinned tag `b10333`) through the
   NDK. Pulled automatically at build time via CMake `FetchContent` — no submodule
   to init.
-- **Model:** `Qwen3.5-2B-Uncensored-HauhauCS-Aggressive-Q4_K_M.gguf` (~1.2 GB) is
+- **Model:** `Qwen3.5-2B-Uncensored-HauhauCS-Aggressive-Q8_0.gguf` (~1.9 GB) is
   **downloaded on first launch** from Hugging Face into the app's private storage.
-  It is *not* bundled in the APK.
+  It is *not* bundled in the APK. (Swap the quant in `ModelDownloader.kt`.)
+- **Persona:** set via `SYSTEM_PROMPT` in `MainActivity.kt`; sampling is a little
+  hot (temp 0.9) for playful answers.
 - **Conversation:** the web layer holds the full history and sends it each turn;
   native rebuilds the ChatML prompt and clears the KV cache before every reply, so
   "new tsjet" is just: clear JS state + reset cache.
@@ -41,7 +45,7 @@ Talk to the tsjet. Hit **new tsjet** to wipe the conversation and start fresh.
   in **Android Studio** (it will offer to install the matching NDK `27.2.12479018`
   and CMake `3.22.1`).
 - **A phone:** 64-bit ARM (`arm64-v8a`), Android 8.0+ (minSdk 26), and enough free
-  RAM to hold a ~1.2 GB Q4 model (~3–4 GB RAM device recommended).
+  RAM to hold a ~1.9 GB Q8 model (~4+ GB RAM device recommended).
 - Network on first launch to download the model.
 
 ## Build