Add direct session URL route

frontend/app/app/assistant.tsx

@@ -7,11 +7,15 @@ import {
 	useChatRuntime,
 } from "@assistant-ui/react-ai-sdk";
 import type { UIMessage } from "ai";
-import { useCallback, useMemo } from "react";
+import { useCallback, useEffect, useMemo, useRef } from "react";
 import {
 	ActivityPanel,
 	ActivityProvider,
 } from "@/components/assistant-ui/activity-panel";
+import {
+	fetchLatestRunStatus,
+	toReplayRepository,
+} from "@/components/assistant-ui/thread-list";
 import { Thread } from "@/components/assistant-ui/thread";
 import { ThreadListSidebar } from "@/components/assistant-ui/threadlist-sidebar";
 import {
@@ -27,8 +31,13 @@ import {
 import { ClawSessionReplayProvider } from "@/lib/claw-session-replay";
 import { ClawAccountGate, useClawAccount } from "./claw-account-gate";
 
-export const Assistant = () => {
+type AssistantProps = {
+	initialSessionId?: string;
+};
+
+export const Assistant = ({ initialSessionId }: AssistantProps = {}) => {
 	const { account, isLoading, setAccount } = useClawAccount();
+	const loadedInitialSessionRef = useRef<string | null>(null);
 	const transport = useMemo(
 		() =>
 			new AssistantChatTransport({
@@ -81,6 +90,41 @@ export const Assistant = () => {
 		[runtime],
 	);
 
+	useEffect(() => {
+		const sessionId = initialSessionId?.trim();
+		if (!account || !sessionId) return;
+		if (loadedInitialSessionRef.current === sessionId) return;
+		loadedInitialSessionRef.current = sessionId;
+		const targetSessionId = sessionId;
+		let cancelled = false;
+
+		async function loadSession() {
+			try {
+				writeActiveSessionId(targetSessionId);
+				const response = await fetch(`/api/claw/sessions/${targetSessionId}`, {
+					cache: "no-store",
+				});
+				if (!response.ok || cancelled) return;
+				const payload = await response.json();
+				const runStatus = await fetchLatestRunStatus(targetSessionId);
+				if (cancelled) return;
+				replaySession(
+					targetSessionId,
+					toReplayRepository(payload, targetSessionId, runStatus),
+				);
+			} catch {
+				if (!cancelled) {
+					loadedInitialSessionRef.current = null;
+				}
+			}
+		}
+
+		void loadSession();
+		return () => {
+			cancelled = true;
+		};
+	}, [account, initialSessionId, replaySession]);
+
 	if (isLoading) {
 		return (
 			<div className="flex min-h-dvh items-center justify-center bg-background text-muted-foreground text-sm">

frontend/app/app/session/[sessionId]/page.tsx

@@ -0,0 +1,10 @@
+import { Assistant } from "../../assistant";
+
+export default async function SessionPage({
+	params,
+}: {
+	params: Promise<{ sessionId: string }>;
+}) {
+	const { sessionId } = await params;
+	return <Assistant initialSessionId={decodeURIComponent(sessionId)} />;
+}