fix: add 16KB page alignment support for Android

rust/.cargo/config.toml

@@ -0,0 +1,16 @@
+# Ensure 16KB page alignment for Android targets.
+# Required by Google Play for Android 15+ (API 35+) compatibility.
+# NDK r28+ defaults to this, but explicit flags ensure alignment
+# regardless of NDK version or manual build configuration.
+
+[target.aarch64-linux-android]
+rustflags = ["-C", "link-arg=-Wl,-z,max-page-size=16384"]
+
+[target.armv7-linux-androideabi]
+rustflags = ["-C", "link-arg=-Wl,-z,max-page-size=16384"]
+
+[target.i686-linux-android]
+rustflags = ["-C", "link-arg=-Wl,-z,max-page-size=16384"]
+
+[target.x86_64-linux-android]
+rustflags = ["-C", "link-arg=-Wl,-z,max-page-size=16384"]

rust/cargokit.yaml

@@ -1,6 +1,10 @@
 cargo:
   release:
     toolchain: stable
-precompiled_binaries:
-  url_prefix: https://github.com/LtbLightning/bdk-flutter/releases/download/precompiled_
-  public_key: 0e43d5e8452d00db7f3000c18fb1ba796babfcb5dc6306bb0629eff24f8be85b
+# Disabled: precompiled binaries are built with 4KB page alignment (0x1000).
+# Google Play now requires 16KB alignment (0x4000) for native libraries.
+# Building from source with NDK r28+ produces correct 16KB alignment.
+# Re-enable once precompiled binaries are rebuilt with 16KB page alignment.
+# precompiled_binaries:
+#   url_prefix: https://github.com/LtbLightning/bdk-flutter/releases/download/precompiled_
+#   public_key: 0e43d5e8452d00db7f3000c18fb1ba796babfcb5dc6306bb0629eff24f8be85b