chat: put the session list cwd in the url, not a panel channel

Which project group you are looking at is addressable state, so /chat?cwd=<dir> has to be a
link anyone can hand out — it survives a refresh and an agent run can point straight at its
own runs directory. Was usePanelChannel('chat:active-cwd'), which per the navigation audit is
for signals and refresh buses only. Row links and New Chat now carry the query string along.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/apps/officer-web/Screens/Dashboard/ChatHistory/index.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useMemo, useRef } from 'react';
-import { useParams, useNavigate } from 'react-router';
+import { useParams, useNavigate, useSearchParams } from 'react-router';
 import type { LayoutNode, SelectedSession } from 'officerdev';
 import { WorkspaceView } from 'officerdev';
 import { useIsMobile } from 'hooks/useIsMobile';
@@ -38,7 +38,7 @@ type SessionListPageProps = {
 export const SessionListPage = ({ isNew }: SessionListPageProps) => {
   const { sessionId } = useParams<{ sessionId: string }>();
   const [selected, setSelected] = usePanelChannel<SelectedSession>('chat:selected-session', null);
-  const [, setActiveCwd] = usePanelChannel<string | null>('chat:active-cwd', null);
+  const [, setSearchParams] = useSearchParams();
   const client = useClient();
   const selectedRef = useRef(selected);
   selectedRef.current = selected;
@@ -78,7 +78,16 @@ export const SessionListPage = ({ isNew }: SessionListPageProps) => {
       try {
         const detail = await client.get<ClaudeSessionDetail>(`/chat/sessions/${sessionId}?limit=${CHAT_TAIL}`);
         if (cancelled) return;
-        setActiveCwd(detail.cwd || null);
+        // replace: resolving a deep link is a canonicalisation, not a navigation the back button owes you.
+        setSearchParams(
+          (prev) => {
+            const next = new URLSearchParams(prev);
+            if (detail.cwd) next.set('cwd', detail.cwd);
+            else next.delete('cwd');
+            return next;
+          },
+          { replace: true },
+        );
         setSelected({
           id: sessionId,
           model: detail.model,

src/workspaces/officerdev/src/apps/ChatHistory/ChatDetailPanel.tsx

@@ -1,5 +1,5 @@
 import { useCallback } from 'react';
-import { useLocation } from 'react-router';
+import { useLocation, useSearchParams } from 'react-router';
 import { Unplug } from 'lucide-react';
 import { usePanelChannel } from 'hooks/usePanelChannel';
 import { useAuth } from 'hooks/useAuth';
@@ -98,8 +98,9 @@ function NewChat({ resumeSummary, resumeSessionId, initialMessages, total, initi
         : undefined,
   });
 
-  // Run the session in the pwd chosen in the Sessions panel; null → backend default (general_chat_sessions).
+  // Run the session in the pwd the URL names; absent → backend default (general_chat_sessions).
-  const [activeCwd] = usePanelChannel<string | null>('chat:active-cwd', null);
+  const [searchParams] = useSearchParams();
+  const activeCwd = searchParams.get('cwd');
   const cwd = activeCwd ? { path: activeCwd } : locationState?.cwd;
 
   const initialMessage = locationState?.initialMessage

src/workspaces/officerdev/src/apps/ChatHistory/SessionList.tsx

@@ -1,5 +1,5 @@
 import { useRef, useState, useCallback } from 'react';
-import { Link, useNavigate } from 'react-router';
+import { Link, useNavigate, useSearchParams } from 'react-router';
 import { Plus, MessageSquare, RefreshCw, Trash2, Pencil, Check, X } from 'lucide-react';
 import { usePanelChannel } from 'hooks/usePanelChannel';
 import { useClaudeSessions } from 'state/useClaudeSessions';
@@ -10,8 +10,12 @@ import { PwdSelector } from './PwdSelector';
 // Clicking a session loads its transcript and continues the real Claude session via --resume.
 export const SessionList = () => {
   const navigate = useNavigate();
-  // The working directory the list operates on (null = the default general_chat_sessions dir).
+  // The working directory the list operates on (absent = the default general_chat_sessions dir).
-  const [activeCwd, setActiveCwd] = usePanelChannel<string | null>('chat:active-cwd', null);
+  // In the URL, not a channel: which project group you're looking at is addressable state, so
+  // /chat?cwd=<dir> has to be a link anyone can hand out — an agent run points at its own group
+  // this way, and it survives a refresh.
+  const [searchParams, setSearchParams] = useSearchParams();
+  const activeCwd = searchParams.get('cwd');
   const { sessions, isLoading, refetch, deleteSession, renameSession } = useClaudeSessions(activeCwd);
   const [selected, setSelected] = usePanelChannel<SelectedSession>('chat:selected-session', null);
   const [editingId, setEditingId] = useState<string | null>(null);
@@ -52,7 +56,15 @@ export const SessionList = () => {
         <PwdSelector
           value={activeCwd}
           onChange={(cwd) => {
-            setActiveCwd(cwd);
+            setSearchParams(
+              (prev) => {
+                const next = new URLSearchParams(prev);
+                if (cwd) next.set('cwd', cwd);
+                else next.delete('cwd');
+                return next;
+              },
+              { replace: true },
+            );
             setSelected(null); // sessions belong to a cwd — clear the open one when switching
           }}
         />
@@ -67,7 +79,8 @@ export const SessionList = () => {
           <button
             onClick={() => {
               setSelected({ id: `new:${Date.now()}` });
-              navigate('/chat/new', { replace: true });
+              // Carry the cwd: a new chat starts in the pwd the list is showing, and that now lives in the URL.
+              navigate({ pathname: '/chat/new', search: searchParams.toString() }, { replace: true });
             }}
             className="flex items-center gap-1.5 rounded-md bg-duck-teal hover:bg-duck-teal/90 text-duck-yellow cursor-pointer h-7 px-3 text-xs font-medium"
           >
@@ -132,7 +145,7 @@ export const SessionList = () => {
               ) : (
                 <>
                   <Link
-                    to={`/chat/${session.id}`}
+                    to={{ pathname: `/chat/${session.id}`, search: searchParams.toString() }}
                     className="flex flex-1 items-center gap-3 px-4 py-3 min-w-0 text-left cursor-pointer"
                   >
                     <MessageSquare className="h-4 w-4 shrink-0 text-duck-teal/60" />