epic: add Android ELF build IDs

[ovitrif]

Goal

Add stable ELF build IDs to every Bitkit-owned Rust Android library and adopt the released artifacts in Bitkit Android so Google Play can match packaged libraries with their uploaded native debug symbols.

Coordination

Producer releases provide the Android artifacts and native debug-symbol archives. Bitkit Android consumes those releases and packages the complete native symbol set for both release ABIs.

Acceptance criteria

• Every Bitkit-owned Rust Android library is linked with a stable ELF build ID in its published artifact.
• Bitkit Android consumes the released LDK, bitkit-core, VSS, and Paykit artifacts.
• The native debug-symbol archive contains libldk_node.so, libbitkitcore.so, libvss_rust_client_ffi.so, and libpaykit.so for both release ABIs.
• The Android integration passes its build, test, lint, and native-symbol archive checks.