Fix expandEnv regex, init script crash, healthcheck deadline, and test issues

- Fix envRegex: remove spurious (\$)? group that swallowed $$$, handle ${}
- wrenn-init.sh: add || true to networking commands under set -e, remove dead code
- waitForHealthcheck: use context deadline for unlimited retries instead of implicit 100 cap
- Make parseSandboxEnv a package-level function (unused receiver)
- Fix WrappedCommand test: map iteration order dependency, pre-expand env values
- Fix error wrapping: %v → %w per project conventions
- test-jupyter-kernel.py: move import to top-level, fix misleading comment

images/wrenn-init.sh

@@ -20,34 +20,14 @@ echo "+cpu +memory +io" > /sys/fs/cgroup/cgroup.subtree_control 2>/dev/null || t
 # Set hostname
 hostname sandbox
 
-# Configure networking from kernel cmdline (ip=client::gw:mask:host:iface:autoconf).
-# if command -v ip >/dev/null 2>&1; then
-#     iparg=$(cat /proc/cmdline | tr ' ' '\n' | sed -n 's/^ip=//p')
-#     if [ -n "$iparg" ]; then
-#         client=$(echo "$iparg" | cut -d: -f1)
-#         gw=$(echo "$iparg" | cut -d: -f2)
-#         mask=$(echo "$iparg" | cut -d: -f3)
-#         iface=$(echo "$iparg" | cut -d: -f5)
-#         [ -z "$iface" ] && iface=eth0
-#         if [ -n "$client" ]; then
-#             ip addr add "$client/${mask:-30}" dev "$iface" 2>/dev/null || true
-#             ip link set "$iface" up 2>/dev/null || true
-#             if [ -n "$gw" ]; then
-#                 ip route add default via "$gw" 2>/dev/null || true
-#             fi
-#         fi
-#     fi
-# fi
-#
-#
+# Configure networking if the kernel ip= boot arg did not already set it up.
 if ! ip addr show eth0 2>/dev/null | grep -q "169.254.0.21"; then
-    ip link set lo up
-    ip link set eth0 up
-    ip addr add 169.254.0.21/30 dev eth0
-    ip route add default via 169.254.0.22
+    ip link set lo up 2>/dev/null || true
+    ip link set eth0 up 2>/dev/null || true
+    ip addr add 169.254.0.21/30 dev eth0 2>/dev/null || true
+    ip route add default via 169.254.0.22 2>/dev/null || true
 fi
 
-
 # Configure DNS resolver.
 echo "nameserver 8.8.8.8" > /etc/resolv.conf
 echo "nameserver 8.8.4.4" >> /etc/resolv.conf