feat(web): add file tree manual refresh + 5s polling + focus refetch

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

web/src/components/workspace/FileExplorerPanel.tsx

@@ -1,4 +1,5 @@
-import { ChevronRight, FileCode2, Folder } from "lucide-react";
+import { useQueryClient, useIsFetching } from "@tanstack/react-query";
+import { ChevronRight, FileCode2, Folder, RefreshCw } from "lucide-react";
 import type { ReactNode } from "react";
 
 import { ScrollArea } from "@/components/ui/scroll-area";
@@ -131,6 +132,9 @@ function EmptyState({ children }: { children: ReactNode }) {
 export function FileExplorerPanel({ workspaceId }: FileExplorerPanelProps) {
   const setActiveFilePath = useWorkspaceUiStore((s) => s.setActiveFilePath);
   const setSelectedPath = useFileTreeStore((s) => s.setSelectedPath);
+  const queryClient = useQueryClient();
+  const filesQueryKey = ["workspaces", workspaceId ?? "", "files"] as const;
+  const isFetchingFiles = useIsFetching({ queryKey: filesQueryKey }) > 0;
   const { data, isLoading, error } = useFileList(workspaceId, ".");
 
   const onSelectFile = (path: string) => {
@@ -138,12 +142,33 @@ export function FileExplorerPanel({ workspaceId }: FileExplorerPanelProps) {
     setActiveFilePath(path);
   };
 
+  const refreshAll = () => {
+    queryClient.invalidateQueries({ queryKey: filesQueryKey });
+  };
+
+  const header = (
+    <div className="flex h-9 shrink-0 items-center justify-between border-b border-sidebar-border px-3 text-[11px] font-semibold uppercase text-muted-foreground">
+      <span>Explorer</span>
+      {workspaceId && (
+        <button
+          type="button"
+          onClick={refreshAll}
+          aria-label="refresh file tree"
+          className="inline-flex h-5 w-5 items-center justify-center rounded text-muted-foreground transition-colors hover:bg-accent hover:text-accent-foreground"
+        >
+          <RefreshCw
+            className={cn("size-3", isFetchingFiles && "animate-spin")}
+            aria-hidden="true"
+          />
+        </button>
+      )}
+    </div>
+  );
+
   if (!workspaceId) {
     return (
       <aside className="flex h-full min-h-0 flex-col bg-sidebar text-sidebar-foreground">
-        <div className="flex h-9 shrink-0 items-center border-b border-sidebar-border px-3 text-[11px] font-semibold uppercase text-muted-foreground">
-          Explorer
-        </div>
+        {header}
         <EmptyState>
           <p>No workspace selected</p>
         </EmptyState>
@@ -153,9 +178,7 @@ export function FileExplorerPanel({ workspaceId }: FileExplorerPanelProps) {
 
   return (
     <aside className="flex h-full min-h-0 flex-col bg-sidebar text-sidebar-foreground">
-      <div className="flex h-9 shrink-0 items-center border-b border-sidebar-border px-3 text-[11px] font-semibold uppercase text-muted-foreground">
-        Explorer
-      </div>
+      {header}
       <ScrollArea className="min-h-0 flex-1">
         <nav className="py-2" aria-label="Workspace files">
           <ul>

web/src/lib/api/files.ts

@@ -100,6 +100,8 @@ export function useFileList(
     queryKey: fileListQueryKey(workspaceId ?? "", queryPath),
     queryFn: () => fetchFileList(workspaceId!, queryPath),
     enabled: !!workspaceId && enabled,
+    refetchInterval: 5_000,
+    refetchOnWindowFocus: true,
   });
 }