fix: zlib parallel build race + Kotlin SNAPSHOT version in release

Two follow-up fixes discovered while validating the v0.19.10 draft release.

1. sdk/runanywhere-web/wasm/scripts/build.sh — cap --parallel at 2

During release.yml native_web, zlib static-lib linking intermittently
raced with llvm-ranlib: two parallel link steps wrote libz.a and another
job tried to ranlib it before the writer had finished, causing "unable
to load 'libz.a': No such file or directory". First hit on the v0.19.10
release run; a rerun succeeded. Capping to 2 workers (we only have 2
cores on standard GH runners) eliminates the race without meaningfully
impacting build time.

2. .github/workflows/release.yml — pass SDK_VERSION env to sdk_kotlin

The v0.19.10 release's JVM JAR was named RunAnywhereKotlinSDK-jvm-
0.1.5-SNAPSHOT.jar instead of using the release version. build.gradle.kts
reads SDK_VERSION from env, falling back to "0.1.5-SNAPSHOT" if unset.
The release workflow wasn't setting it. Now forwards the validated
release version into the gradle invocation.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sanchitmonga22

.github/workflows/release.yml

@@ -293,7 +293,12 @@ jobs:
         # only the packaging tasks directly. Test sources have drifted from
         # the current SDK API and are not part of the release deliverable;
         # that cleanup is a follow-up unrelated to the artifact pipeline.
+        #
+        # SDK_VERSION is consumed by build.gradle.kts (line ~52) to name the
+        # JVM JAR artifact. Without it, it falls back to "0.1.5-SNAPSHOT".
         working-directory: sdk/runanywhere-kotlin
+        env:
+          SDK_VERSION: ${{ needs.validate.outputs.version }}
         run: ./gradlew -Prunanywhere.useLocalNatives=true assembleRelease jvmJar --no-daemon
       - name: Collect Kotlin SDK artifacts
         run: |

sdk/runanywhere-web/wasm/scripts/build.sh

@@ -161,7 +161,11 @@ emcmake cmake \
 # Build
 echo ""
 echo ">>> Building WASM module..."
-emmake cmake --build "${BUILD_DIR}" --parallel
+# Cap parallelism to 2 to avoid an intermittent zlib static-lib race with
+# llvm-ranlib under emmake where two parallel link steps produce and then
+# immediately consume libz.a, and the reader can see it before the writer
+# finishes. 2 workers is plenty on 2-core CI runners and safe locally.
+emmake cmake --build "${BUILD_DIR}" --parallel 2
 
 # Verify outputs
 echo ""