Add session list refresh with server cache bypass

useSession now exposes a refreshSessions() callback that fetches
/api/sessions?refresh=1. The sessions route checks for the refresh
query parameter and resets the cache timestamp to zero, forcing a
fresh scan of ~/.claude/projects/ on the next request.

This enables users to pick up new sessions without restarting the
server or waiting for the 30-second cache to expire.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/client/hooks/useSession.ts

@@ -9,6 +9,7 @@ interface SessionState {
   sessionLoading: boolean;
   sessionError: string | null;
   loadSessions: () => Promise<void>;
+  refreshSessions: () => Promise<void>;
   loadSession: (id: string) => Promise<void>;
 }
 
@@ -21,11 +22,12 @@ export function useSession(): SessionState {
   const [sessionLoading, setSessionLoading] = useState(false);
   const [sessionError, setSessionError] = useState<string | null>(null);
 
-  const loadSessions = useCallback(async () => {
+  const fetchSessions = useCallback(async (refresh = false) => {
     setSessionsLoading(true);
     setSessionsError(null);
     try {
-      const res = await fetch("/api/sessions");
+      const url = refresh ? "/api/sessions?refresh=1" : "/api/sessions";
+      const res = await fetch(url);
       if (!res.ok) throw new Error(`HTTP ${res.status}`);
       const data = await res.json();
       setSessions(data.sessions);
@@ -38,6 +40,9 @@ export function useSession(): SessionState {
     }
   }, []);
 
+  const loadSessions = useCallback(() => fetchSessions(false), [fetchSessions]);
+  const refreshSessions = useCallback(() => fetchSessions(true), [fetchSessions]);
+
   const loadSession = useCallback(async (id: string) => {
     setSessionLoading(true);
     setSessionError(null);
@@ -67,6 +72,7 @@ export function useSession(): SessionState {
     sessionLoading,
     sessionError,
     loadSessions,
+    refreshSessions,
     loadSession,
   };
 }

src/server/routes/sessions.ts

@@ -19,8 +19,11 @@ async function getCachedSessions(): Promise<SessionEntry[]> {
   return cachedSessions;
 }
 
-sessionsRouter.get("/", async (_req, res) => {
+sessionsRouter.get("/", async (req, res) => {
   try {
+    if (req.query.refresh === "1") {
+      cacheTimestamp = 0;
+    }
     const sessions = await getCachedSessions();
     res.json({ sessions });
   } catch (err) {