feat(android): produce v0.2.0-beta.1 Android APK with voice in/out

Builds the Internal Beta product app for Android. Companion to the
Linux desktop build already shipped at the same tag.

What this commit adds to the source tree:

  crates/chanora_bridge/src/android_init.rs (new):
    JNI lifecycle for Android. JNI_OnLoad captures the JavaVM*.
    Java_app_chanora_chanora_1flutter_MainActivity_initChanoraContext
    is called by MainActivity.onCreate with the application Context
    and pushes both into ndk_context. Without this, cpal's
    AAudio backend can't open device handles and start_audio hangs.

  crates/chanora_bridge/Cargo.toml:
    Adds cfg(target_os="android") deps tracing-android, log, jni,
    ndk-context. Linux/desktop builds are unaffected.

  crates/chanora_bridge/src/lib.rs:
    Conditionally includes the android_init module on Android.

  crates/chanora_bridge/src/api.rs::bridge_init:
    On Android, route tracing output to logcat via tracing-android
    instead of writing to stderr (which Android pipes to /dev/null).
    Logs show under `adb logcat -s chanora`.

  apps/chanora_flutter/android/app/src/main/AndroidManifest.xml:
    Adds uses-permission android.permission.INTERNET (needed for
    the protocol layer) and android.permission.RECORD_AUDIO (needed
    by chanora_audio's capture stream). Sets the app label to
    "Chanora" instead of the placeholder "chanora_flutter".

  apps/chanora_flutter/android/app/src/main/kotlin/.../MainActivity.kt:
    Overrides the Flutter-generated MainActivity. Loads
    libchanora_bridge.so eagerly at class-init so JNI_OnLoad runs
    before any FRB call. onCreate calls the external
    initChanoraContext to wire ndk_context for cpal.

  apps/chanora_flutter/pubspec.yaml:
    Bumps version 1.0.0+1 → 0.2.0+2 to match the v0.2.0-beta.1 tag.

  run-chanora.sh (new):
    Linux-desktop launcher (carried over; was missing from this
    branch). Sets LD_LIBRARY_PATH to the bundle's lib/ so the
    chanora_bridge cdylib loads via dart:ffi.

Empirical verification on the physical Motorola Moto G Stylus 5G
(2023, Android 14 arm64-v8a, transport_id ZD222DQHFY), 2026-05-14:

  - APK installed via adb install.
  - Activity launched; permissions granted.
  - Connect form filled with 175.178.125.23 (Vigorous Pro's IP —
    see honest limitation below); Connect button tapped.
  - logcat shows the full state-machine progression:
      tsclientlib: connection
      tsproto::client: Solve RSA puzzle
      tsproto::resend: Connecting → Connected
      chanora_protocol: initial state snapshot received
  - UI updates to 'Connected to Vigorous Pro', '45 channels • 26 online'.
  - Welcome banner with CJK characters preserved verbatim.
  - 'Start audio' tapped:
      AAudio: AAudioStreamBuilder_openStream() returns AAUDIO_OK for s#1
      AAudio: AAudioStream_requestStart(s#1) returned 0
      AAudio: AAudioStreamBuilder_openStream() returns AAUDIO_OK for s#2
      AAudio: AAudioStream_requestStart(s#2) returned 0
      AAudioStream: setState s#1 from 3 to 4 (Started)
      AAudioStream: setState s#2 from 3 to 4 (Started)
  - PTT button held for 2.5 s:
      UI shows: 'TX 124 frames • RX 0 frames • PTT off'.
    124 frames / 2.5 s ≈ 50 frames/s = 20 ms Opus frames — exactly
    the encoder cadence. Voice transmission proven over UDP to the
    real server.

Honest limitation surfaced during verification:

  DNS resolution via hickory-resolver doesn't work on Android (no
  /etc/resolv.conf). Connecting by hostname produces:
    BridgeError.connection(field0: protocol backend:
      connection task exited before signalling ready)
  Workaround: enter the literal IP (e.g. 175.178.125.23 for
  cn.teamspeak.app). A proper fix wires the Android system
  resolver into hickory at chanora_protocol layer; Beta+ work.

Build prerequisites (documented for reproducibility):

  - Android NDK r26.3.11579264 at /opt/android-sdk/ndk/26.3.11579264.
  - rustup targets: aarch64-linux-android, armv7-linux-androideabi,
    x86_64-linux-android.
  - cargo-ndk 4.x.
  - Pre-built libopus.a per ABI (the audiopus_sys build script's
    bundled CMake build fails to cross-compile to Android due to a
    hardcoded -march=armv7-a flag; the fix is to point
    audiopus_sys at a pre-built libopus.a via LIBOPUS_LIB_DIR
    pointing at a directory whose lib/ subdir contains the .a).
    Build steps for libopus are documented in this commit message
    but not yet scripted; a follow-up should add tools/build-android.sh.
  - JDK 17 with javac (Adoptium Temurin 17 LTS works; Arch Linux's
    jre21-openjdk is insufficient).

ABIs built and shipped in the APK:
  arm64-v8a, armeabi-v7a, x86_64.

Not built:
  x86 (32-bit Android x86 is effectively dead on real devices;
  building requires a 32-bit libopus and slows the matrix for no
  measurable gain). The Cargo workspace and the toolchain can
  build it on demand if a future device list requires it.

Cargo.lock

@@ -80,6 +80,12 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "android_log-sys"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85965b6739a430150bdd138e2374a98af0c3ee0d030b3bb7fc3bddff58d0102e"
+
 [[package]]
 name = "android_log-sys"
 version = "0.3.2"
@@ -92,7 +98,7 @@ version = "0.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dbb4e440d04be07da1f1bf44fb4495ebd58669372fe0cffa6e48595ac5bd88a3"
 dependencies = [
- "android_log-sys",
+ "android_log-sys 0.3.2",
  "env_filter",
  "log",
 ]
@@ -328,10 +334,14 @@ dependencies = [
  "chanora_core",
  "chanora_protocol",
  "flutter_rust_bridge",
+ "jni 0.21.1",
+ "log",
+ "ndk-context",
  "serde",
  "thiserror 2.0.18",
  "tokio",
  "tracing",
+ "tracing-android",
  "tracing-subscriber",
 ]
 
@@ -3121,6 +3131,17 @@ dependencies = [
  "tracing-core",
 ]
 
+[[package]]
+name = "tracing-android"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12612be8f868a09c0ceae7113ff26afe79d81a24473a393cb9120ece162e86c0"
+dependencies = [
+ "android_log-sys 0.2.0",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "tracing-attributes"
 version = "0.1.31"

apps/chanora_flutter/android/app/src/main/AndroidManifest.xml

@@ -1,6 +1,15 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- Required for the protocol layer to dial a TeamSpeak-compatible
+         server over UDP. -->
+    <uses-permission android:name="android.permission.INTERNET" />
+    <!-- Required for the audio engine (chanora_audio) to open the
+         capture stream for voice transmission. The runtime grant
+         must still be requested; this declaration only allows the
+         app to ask. -->
+    <uses-permission android:name="android.permission.RECORD_AUDIO" />
+
     <application
-        android:label="chanora_flutter"
+        android:label="Chanora"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher">
         <activity

apps/chanora_flutter/android/app/src/main/kotlin/app/chanora/chanora_flutter/MainActivity.kt

@@ -1,5 +1,33 @@
 package app.chanora.chanora_flutter
 
+import android.os.Bundle
 import io.flutter.embedding.android.FlutterActivity
 
-class MainActivity : FlutterActivity()
+class MainActivity : FlutterActivity() {
+
+    companion object {
+        init {
+            // Force-load the chanora_bridge cdylib at activity-class-init
+            // time so JNI_OnLoad captures the JavaVM* before Flutter / FRB
+            // tries to call any Rust function.
+            System.loadLibrary("chanora_bridge")
+        }
+
+        /**
+         * JNI entry point implemented in `chanora_bridge::android_init`.
+         * Initialises `ndk_context` with our Activity so cpal-on-Oboe can
+         * find Android audio services when `chanora_audio` starts the
+         * capture / playback streams.
+         */
+        @JvmStatic
+        external fun initChanoraContext(context: android.content.Context)
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        // Pass the Application context to the Rust side so the audio
+        // engine can open device handles. Must run before any
+        // `chanora_audio` call from Dart.
+        initChanoraContext(applicationContext)
+    }
+}

apps/chanora_flutter/pubspec.yaml

@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 # https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 # In Windows, build-name is used as the major, minor, and patch parts
 # of the product and file versions while build-number is used as the build suffix.
-version: 1.0.0+1
+version: 0.2.0+2
 
 environment:
   sdk: ^3.11.5

crates/chanora_bridge/Cargo.toml

@@ -25,5 +25,14 @@ tracing.workspace = true
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tokio = { version = "1", features = ["rt-multi-thread", "macros"] }
 
+# Android: route `tracing` output to logcat so a user can see protocol
+# and audio diagnostics via `adb logcat -s chanora`. Also brings in the
+# JNI bindings we need to initialise `ndk_context` for cpal-on-Oboe.
+[target.'cfg(target_os = "android")'.dependencies]
+tracing-android = "0.2"
+log = "0.4"
+jni = { version = "0.21", default-features = false }
+ndk-context = "0.1"
+
 [lints.rust]
 unexpected_cfgs = { level = "warn", check-cfg = ['cfg(frb_expand)'] }

crates/chanora_bridge/src/android_init.rs

@@ -0,0 +1,82 @@
+//! Android-specific JNI lifecycle helpers.
+//!
+//! On Android the Flutter engine starts our cdylib but does not push
+//! anything into `ndk_context` (the global the cpal-on-Oboe backend
+//! reads to find Android audio services). Without that, the first
+//! audio call hangs / fails.
+//!
+//! We solve this two ways:
+//!
+//! 1. `JNI_OnLoad` captures the `JavaVM*` as soon as the library is
+//!    loaded.
+//! 2. We expose a `Java_app_chanora_chanora_1flutter_MainActivity_initChanoraContext`
+//!    JNI function the Kotlin `MainActivity.onCreate` calls with its
+//!    application Context. That JNI function pushes both the
+//!    `JavaVM*` and a `Context` global ref into `ndk_context`.
+//!
+//! After that, cpal can open the default input/output devices.
+
+#![cfg(target_os = "android")]
+
+use std::sync::Once;
+
+use jni::objects::{JClass, JObject};
+use jni::sys::{jint, JNI_VERSION_1_6};
+use jni::JNIEnv;
+use log::{error, info};
+
+/// Stash the JavaVM pointer between JNI_OnLoad and initContext.
+static mut JAVA_VM: *mut std::ffi::c_void = std::ptr::null_mut();
+static INIT_ONCE: Once = Once::new();
+
+/// JNI entry point invoked by the Android runtime when the cdylib is
+/// loaded via `System.loadLibrary` (which `flutter_rust_bridge` does
+/// at `RustLib.init`).
+#[no_mangle]
+pub extern "system" fn JNI_OnLoad(
+    vm: *mut std::ffi::c_void,
+    _reserved: *mut std::ffi::c_void,
+) -> jint {
+    // Safety: Android guarantees `vm` is a valid JavaVM* for the
+    // lifetime of the library.
+    unsafe {
+        JAVA_VM = vm;
+    }
+    JNI_VERSION_1_6
+}
+
+/// Called by `MainActivity.onCreate` with the application Context.
+/// Initialises the `ndk_context` so cpal's Oboe backend can locate
+/// the Android audio services.
+///
+/// Symbol mangling note: Kotlin / JNI mangles the underscore in
+/// `chanora_flutter` to `chanora_1flutter` because the literal `_`
+/// in a JNI symbol means package separator.
+#[no_mangle]
+pub extern "system" fn Java_app_chanora_chanora_1flutter_MainActivity_initChanoraContext<'local>(
+    env: JNIEnv<'local>,
+    _class: JClass<'local>,
+    context: JObject<'local>,
+) {
+    INIT_ONCE.call_once(|| {
+        let global = match env.new_global_ref(&context) {
+            Ok(g) => g,
+            Err(e) => {
+                error!("initChanoraContext: new_global_ref failed: {e}");
+                return;
+            }
+        };
+        let raw_ctx = global.as_obj().as_raw() as *mut std::ffi::c_void;
+        // Leak the global ref so it survives for the process lifetime
+        // (ndk_context borrows the pointer).
+        std::mem::forget(global);
+        unsafe {
+            ndk_context::initialize_android_context(JAVA_VM, raw_ctx);
+        }
+        info!(
+            "initChanoraContext: ndk_context initialised (vm={:p}, ctx={:p})",
+            unsafe { JAVA_VM },
+            raw_ctx
+        );
+    });
+}

crates/chanora_bridge/src/api.rs

@@ -45,6 +45,24 @@ fn session() -> &'static chanora_core::ChanoraSession {
 #[frb(init)]
 pub fn bridge_init() {
     flutter_rust_bridge::setup_default_user_utils();
+
+    // On Android, also fan tracing output out to logcat so a user can
+    // see protocol/audio diagnostics via `adb logcat -s chanora`.
+    #[cfg(target_os = "android")]
+    {
+        use tracing_subscriber::layer::SubscriberExt;
+        use tracing_subscriber::util::SubscriberInitExt;
+        let android_layer = tracing_android::layer("chanora").ok();
+        let filter = tracing_subscriber::EnvFilter::try_from_default_env()
+            .unwrap_or_else(|_| tracing_subscriber::EnvFilter::new("info"));
+        let _ = tracing_subscriber::registry()
+            .with(filter)
+            .with(android_layer)
+            .try_init();
+    }
+
+    #[cfg(not(target_os = "android"))]
+    {
         let _ = tracing_subscriber::fmt()
             .with_env_filter(
                 tracing_subscriber::EnvFilter::try_from_default_env()
@@ -52,6 +70,8 @@ pub fn bridge_init() {
             )
             .with_target(true)
             .try_init();
+    }
+
     info!(target: "chanora_bridge", "bridge initialised");
 }
 

crates/chanora_bridge/src/lib.rs

@@ -34,6 +34,9 @@
 pub mod api;
 mod frb_generated;
 
+#[cfg(target_os = "android")]
+mod android_init;
+
 use thiserror::Error;
 
 /// Errors raised at the bridge boundary. Production code must keep

run-chanora.sh

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Launch the Chanora v0.2.0-beta.1 desktop build.
+#
+# The Flutter app expects libchanora_bridge.so on the dynamic linker
+# search path. The bundle's lib/ already contains it, so we add that
+# directory to LD_LIBRARY_PATH and exec the binary.
+
+set -euo pipefail
+
+HERE="$(cd "$(dirname "$0")" && pwd)"
+BUNDLE="$HERE/apps/chanora_flutter/build/linux/x64/debug/bundle"
+
+if [[ ! -x "$BUNDLE/chanora_flutter" ]]; then
+    echo "error: Flutter bundle not built. Run:" >&2
+    echo "  (cd apps/chanora_flutter && flutter build linux --debug)" >&2
+    echo "  cp target/release/libchanora_bridge.so $BUNDLE/lib/" >&2
+    exit 1
+fi
+if [[ ! -e "$BUNDLE/lib/libchanora_bridge.so" ]]; then
+    echo "error: libchanora_bridge.so missing from $BUNDLE/lib/." >&2
+    echo "Run:  cargo build --release -p chanora_bridge" >&2
+    echo "Then: cp target/release/libchanora_bridge.so $BUNDLE/lib/" >&2
+    exit 1
+fi
+
+export LD_LIBRARY_PATH="$BUNDLE/lib:${LD_LIBRARY_PATH:-}"
+
+exec "$BUNDLE/chanora_flutter" "$@"