feat(core): event queue, Ethernet, switch, ARP, IPv4, ICMP, routing and firewall

First slice of the TypeScript port of the filius-ipad runtime engine,
with 29 tests ported from the Swift suite. Parts not ported yet throw
NotPortedError instead of guessing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/core/src/ids.ts

@@ -0,0 +1,19 @@
+// Ported from filius-ipad (GPLv2/GPLv3), ios/FiliusPad/TopologyEditor.
+// Swift orders identifiers by `UUID.uuidString`, which is upper case. Every
+// deterministic ordering in the runtime depends on it, so identifiers are
+// compared the same way here whatever case they were written in.
+
+/** A node, port, link or socket identifier: a UUID string. */
+export type Id = string;
+
+/** `lhs.uuidString < rhs.uuidString` in Swift. */
+export function idLess(lhs: Id, rhs: Id): boolean {
+  return lhs.toUpperCase() < rhs.toUpperCase();
+}
+
+/** Comparator for `Array.prototype.sort` with the Swift ordering. */
+export function compareIds(lhs: Id, rhs: Id): number {
+  const left = lhs.toUpperCase();
+  const right = rhs.toUpperCase();
+  return left < right ? -1 : left > right ? 1 : 0;
+}