Fix container start failure on Pi: disable cgroup swap limit

Raspberry Pi OS does not enable swap accounting in cgroups by default,
so the memory.swap.max cgroup v2 file does not exist.  Setting --memory
without --memory-swap causes runc to write a swap limit to that file,
which fails with ENOENT.

Adding --memory-swap=-1 tells runc to leave swap unlimited, skipping
the memory.swap.max write entirely.

https://claude.ai/code/session_01FKCW3FDjNFj6jve4niMFXH

builder/build.sh

@@ -106,6 +106,7 @@ podman run --detach \
     --label "hiy.port=${PORT}" \
     --restart unless-stopped \
     --memory="512m" \
+    --memory-swap=-1 \
     --cpus="0.5" \
     "$IMAGE_TAG"