feat(agent): support Responses steering and project-aware tools

Use the dedicated TJWATER_AGENT_URL and Responses stream protocol. Keep running
turns active while users steer or queue follow-ups and edit pending delivery.
Refresh the model catalog before generation and preserve approval mode selection.

Integrate scoped investigation messaging/presentation, geographic place selection,
current Agent composer styles and supporting workbench contracts.

Validation: 77 focused Vitest checks, 21 browser cases, lint, typecheck and
production build. Preserve direct Server/Agent routing and project authentication.

src/features/agent/hooks/use-agent-message-inbox.ts

@@ -0,0 +1,44 @@
+import { useCallback, useEffect, useRef, useState } from "react";
+import useSWR from "swr";
+import type { AgentApiClient } from "../api/client";
+
+export function useAgentMessageInbox(client: AgentApiClient, sessionId: string | null) {
+  const inbox = useSWR(sessionId ? ["agent-message-inbox", sessionId] : null,
+    ([, id]) => client.listAgentMessages(id), { revalidateOnFocus: true, shouldRetryOnError: false });
+  const [loadingMore, setLoadingMore] = useState(false);
+  const mutate = inbox.mutate;
+  const refresh = useCallback(() => { void mutate().catch(() => undefined); }, [mutate]);
+  const refreshRef = useRef(refresh);
+  useEffect(() => { refreshRef.current = refresh; }, [refresh]);
+  useEffect(() => {
+    if (!sessionId) return;
+    const controller = new AbortController();
+    let timer: ReturnType<typeof setTimeout> | undefined;
+    let retryDelay = 1500;
+    function subscribe() {
+      void client.streamAgentMessages(sessionId!, { signal: controller.signal, onMessage: () => { retryDelay = 1500; refreshRef.current(); } })
+        .catch(() => { retryDelay = Math.min(retryDelay * 2, 30_000); })
+        .finally(() => {
+          if (!controller.signal.aborted) timer = setTimeout(subscribe, retryDelay);
+        });
+    }
+    subscribe();
+    return () => { controller.abort(); clearTimeout(timer); };
+  }, [client, sessionId]);
+  return {
+    messages: inbox.data?.items ?? [],
+    hasMore: Boolean(inbox.data?.next_cursor),
+    loading: inbox.isLoading,
+    error: inbox.error ? "任务消息暂时无法加载" : null,
+    refresh,
+    loadingMore,
+    loadMore: async () => {
+      if (!sessionId || !inbox.data?.next_cursor || loadingMore) return;
+      setLoadingMore(true);
+      try {
+        const page = await client.listAgentMessages(sessionId, { cursor: inbox.data.next_cursor });
+        await inbox.mutate((current) => current ? { items: [...current.items, ...page.items.filter((item) => !current.items.some((existing) => existing.message_id === item.message_id))], next_cursor: page.next_cursor } : page, { revalidate: false });
+      } finally { setLoadingMore(false); }
+    }
+  };
+}