Add Android control app and embedded server

Inspired by HNKServer/honoka-chan-apk-server, but implemented as a JNI-based embedded runtime instead of the original approach.

- Add an Android Compose controller app that starts and stops honoka-chan through JNI, shows runtime and health status, manages data directory mounting, and supports backup import/export for data.db
- Add an embeddable Go server entrypoint plus JNI-exported status, health, and reload hooks so desktop and Android builds share the same startup and shutdown path
- Add Android build scripts, runtime packaging, and project documentation, including generated default config.json content for honoka_runtime.zip
- Add runtime bundle hash tracking so updated honoka_runtime.zip assets are automatically redeployed while preserving config.json and user data files
- Add in-app service settings for unlock_all_special_rotation with immediate config persistence and automatic reload when the service is running
- Split SQLite driver selection by platform, using go-sqlite3 on Android and modernc.org/sqlite elsewhere to avoid Android x86_64 seccomp crashes
- Update startup, database initialization, and system health/reload handlers to support the embedded runtime and Android control flow

Signed-off-by: Sean Du <do4suki@gmail.com>

android/scripts/build_go_android.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+source "$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)/common.sh"
+
+require_cmd go
+
+ABI="${1:-arm64-v8a}"
+MIN_SDK="${MIN_SDK:-26}"
+NDK_ROOT="${ANDROID_NDK_HOME:-${ANDROID_NDK_ROOT:-}}"
+
+[[ -n "$NDK_ROOT" ]] || die "ANDROID_NDK_HOME is not set"
+[[ -d "$NDK_ROOT" ]] || die "ANDROID_NDK_HOME does not exist: $NDK_ROOT"
+
+HOST_TAG="${ANDROID_NDK_HOST_TAG:-linux-x86_64}"
+TOOLCHAIN="$NDK_ROOT/toolchains/llvm/prebuilt/$HOST_TAG/bin"
+[[ -d "$TOOLCHAIN" ]] || die "NDK toolchain not found: $TOOLCHAIN"
+
+case "$ABI" in
+  arm64-v8a)
+    export GOOS=android
+    export GOARCH=arm64
+    export CGO_ENABLED=1
+    export CC="$TOOLCHAIN/aarch64-linux-android${MIN_SDK}-clang"
+    OUTPUT_DIR="$ANDROID_DIR/app/src/main/jniLibs/arm64-v8a"
+    ;;
+  armeabi-v7a)
+    export GOOS=android
+    export GOARCH=arm
+    export GOARM=7
+    export CGO_ENABLED=1
+    export CC="$TOOLCHAIN/armv7a-linux-androideabi${MIN_SDK}-clang"
+    OUTPUT_DIR="$ANDROID_DIR/app/src/main/jniLibs/armeabi-v7a"
+    ;;
+  x86_64)
+    export GOOS=android
+    export GOARCH=amd64
+    export CGO_ENABLED=1
+    export CC="$TOOLCHAIN/x86_64-linux-android${MIN_SDK}-clang"
+    OUTPUT_DIR="$ANDROID_DIR/app/src/main/jniLibs/x86_64"
+    ;;
+  *)
+    die "unsupported abi: $ABI"
+    ;;
+esac
+
+[[ -x "$CC" ]] || die "clang not found: $CC"
+
+mkdir -p "$OUTPUT_DIR"
+
+cd "$PROJECT_ROOT"
+
+log "building Go shared library for $ABI"
+go build -trimpath -buildmode=c-shared \
+  -ldflags="-s -w" \
+  -o "$OUTPUT_DIR/libhonokachan.so" \
+  ./cmd/honoka-android
+
+rm -f "$OUTPUT_DIR/libhonokachan.h"
+
+log "built $OUTPUT_DIR/libhonokachan.so"