refactor: rename inspect to replay across the codebase

Renames inspect-ui/ to replay-ui/, internal/inspect/ to internal/replay/,
the CLI subcommand from `sanderling inspect` to `sanderling replay`, and
updates all references in docs, Makefile, README, and Go comments.

replay-ui/src/hooks/useSse.ts

@@ -0,0 +1,18 @@
+import { useEffect } from "react";
+
+export function useSse(eventName: string, onEvent: () => void) {
+  useEffect(() => {
+    if (typeof EventSource === "undefined") {
+      return;
+    }
+    const source = new EventSource("/api/events");
+    const messageHandler = () => {
+      onEvent();
+    };
+    source.addEventListener(eventName, messageHandler);
+    return () => {
+      source.removeEventListener(eventName, messageHandler);
+      source.close();
+    };
+  }, [eventName, onEvent]);
+}