fix: publish android debug symbols

[ovitrif]

Refs synonymdev/bitkit-android#982

Summary

• Unblocks fix: retain native debug symbols bitkit-android#988 by publishing ldk-node-android artifacts with usable native symbol metadata.
• Bumps the Synonym fork package versions to 0.7.0-rc.48.
• Regenerates Android JNI libs with cargo ndk --no-strip so the published AAR can feed Bitkit Android's native-debug-symbols.zip.
• Uses Android NDK r28c and explicit Android linker flags for 16 KB LOAD segment alignment.
• Fails Android binding generation if libldk_node.so lacks .symtab, .debug_*, or .gnu_debugdata for any Android ABI.
• Validates 16 KB LOAD alignment with wide readelf/llvm-readelf program-header output.
• Preserves libldk_node.so symbols through Gradle release AAR packaging.
• Updates the Android publish workflow to regenerate bindings before Gradle build/publish.

Release

• GitHub release: https://github.com/synonymdev/ldk-node/releases/tag/v0.7.0-rc.48
• Android package: https://github.com/synonymdev/ldk-node/packages/2869634?version=0.7.0-rc.48
• Android publish workflow: https://github.com/synonymdev/ldk-node/actions/runs/27030312422
• Consumed by Android PR: fix: retain native debug symbols bitkit-android#988

Validation

• Passed: Android package publish workflow for com.synonym:ldk-node-android:0.7.0-rc.48.
• Passed: ANDROID_NDK_ROOT=/Users/ovitrif/Library/Android/sdk/ndk/28.1.13356709 LLVM_ARCH_PATH=darwin-x86_64 BINDGEN_GOBLEY_INSTALLED=1 scripts/uniffi_bindgen_generate_kotlin_android.sh.
• Passed: bindings/kotlin/ldk-node-android/gradlew --project-dir bindings/kotlin/ldk-node-android build -Pversion=0.7.0-rc.48.
• Passed: bash -n scripts/uniffi_bindgen_generate_kotlin_android.sh.
• Passed: cargo fmt --check (stable rustfmt prints warnings for nightly-only config keys).
• Passed: git diff --check.
• Verified with llvm-readelf -S: generated Android libldk_node.so includes .symtab and .debug_* sections.
• Verified with llvm-readelf -W -l: generated Android arm64-v8a/libldk_node.so LOAD alignment is 0x4000.
• Verified Swift checksum: afadaec20a4d580b877282da609d7882233a8a1137f8cb621c894892aa3dbaae.
• Publish-workflow behavior from this PR can be verified automatically after merge.