fix: increase API memory to 4GB and CPU to 2 cores

Resolves memory limit exceeded errors (2051 MiB > 2048 MiB limit)
that were causing 500 errors on sandbox execute endpoints.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: iamjr15

.github/workflows/docker-build.yml

@@ -69,8 +69,8 @@ jobs:
             --image=${{ env.REGISTRY }}/${{ env.PROJECT_ID }}/${{ env.REPOSITORY }}/api:latest \
             --platform=managed \
             --allow-unauthenticated \
-            --cpu=1 \
-            --memory=2Gi \
+            --cpu=2 \
+            --memory=4Gi \
             --timeout=3500 \
             --min-instances=0 \
             --max-instances=5 \