Split view, personal modes, budget warnings, server move script

- Up to three chats side by side (#/s/a+b+c), "Open beside" in the sidebar menu
- File manager tabs of a chat stored per user on the server (/sessions/{id}/tabs)
- Personal modes for every user (Settings → My modes, /account/modes)
- Budget meters (total, provider, images, opencode Go windows) with push warnings
  for admins at the warning share and 100 %, shown in the status overlay
- scripts/move-server.sh: move to another Docker host with bind mounts (Unraid);
  scripts/smoke-test.sh

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/components/ChatTabs.tsx

@@ -1,5 +1,5 @@
-import { lazy, Suspense, useCallback, useEffect, useState } from "react";
-import { del, get, post } from "../api";
+import { lazy, Suspense, useCallback, useEffect, useRef, useState } from "react";
+import { del, get, post, put } from "../api";
 import { confirmDialog, toast } from "../dialogs";
 import { useT } from "../i18n";
 import { Icon } from "./Icon";
@@ -11,31 +11,24 @@ const Files = lazy(() => import("./Files").then((m) => ({ default: m.Files })));
 
 const POLL_MS = 15_000;
 const tabKey = (sessionId: string) => `codecraft.chatTab.${sessionId}`;
-const filesKey = (sessionId: string) => `codecraft.chatFiles.${sessionId}`;
 
-/** A file manager tab: lives in this browser (it has no server state). */
+/** A file manager tab (stored per user and chat on the server). */
 interface FileTab {
   id: string;
   dir: string;
 }
 
-const loadFileTabs = (sessionId: string): FileTab[] => {
-  try {
-    return JSON.parse(localStorage.getItem(filesKey(sessionId)) ?? "[]");
-  } catch {
-    return [];
-  }
-};
-
 /**
- * Tabs of a chat: the chat itself, its terminals and file managers. Terminals live on
- * the server until closed, so they show up again after a reload or on another device
- * (the list is refreshed periodically); file manager tabs are kept per browser.
+ * Tabs of a chat: the chat itself, its terminals and file managers. Both are kept on the
+ * server, so they show up again after a reload or on another device (the list is
+ * refreshed periodically); which tab is active is per browser tab.
  */
 export function useChatTabs(sessionId: string, cwd: string) {
   const t = useT();
   const [terms, setTerms] = useState<TermInfo[]>([]);
-  const [files, setFilesState] = useState<FileTab[]>(() => loadFileTabs(sessionId));
+  const [files, setFilesState] = useState<FileTab[]>([]);
+  // Local file tab changes not yet saved: polling must not undo them.
+  const pending = useRef<ReturnType<typeof setTimeout> | undefined>(undefined);
   const [tab, setTabState] = useState<string>(() => sessionStorage.getItem(tabKey(sessionId)) ?? "chat");
 
   const setTab = useCallback(
@@ -46,10 +39,14 @@ export function useChatTabs(sessionId: string, cwd: string) {
     [sessionId],
   );
   const setFiles = useCallback(
-    (update: (f: FileTab[]) => FileTab[]) =>
+    (update: (f: FileTab[]) => FileTab[], delay = 0) =>
       setFilesState((cur) => {
         const next = update(cur);
-        localStorage.setItem(filesKey(sessionId), JSON.stringify(next));
+        clearTimeout(pending.current);
+        pending.current = setTimeout(() => {
+          pending.current = undefined;
+          void put(`/sessions/${sessionId}/tabs`, next).catch((e) => toast(e));
+        }, delay);
         return next;
       }),
     [sessionId],
@@ -57,15 +54,18 @@ export function useChatTabs(sessionId: string, cwd: string) {
 
   const reload = useCallback(
     () =>
-      get<TermInfo[]>(`/terminals?session=${encodeURIComponent(sessionId)}`)
-        .then(setTerms)
+      get<{ terminals: TermInfo[]; files: FileTab[] }>(`/sessions/${sessionId}/tabs`)
+        .then((r) => {
+          setTerms(r.terminals);
+          if (!pending.current) setFilesState(r.files);
+        })
         .catch(() => undefined),
     [sessionId],
   );
 
   useEffect(() => {
     setTabState(sessionStorage.getItem(tabKey(sessionId)) ?? "chat");
-    setFilesState(loadFileTabs(sessionId));
+    setFilesState([]);
     setTerms([]);
     void reload();
     const id = setInterval(reload, POLL_MS);
@@ -110,7 +110,8 @@ export function useChatTabs(sessionId: string, cwd: string) {
     if (tab === id) setTab("chat");
   };
 
-  const fileDirChanged = useCallback((id: string, dir: string) => setFiles((f) => f.map((x) => (x.id === id ? { ...x, dir } : x))), [setFiles]);
+  // Browsing saves the folder after a short pause, not on every click.
+  const fileDirChanged = useCallback((id: string, dir: string) => setFiles((f) => f.map((x) => (x.id === id ? { ...x, dir } : x)), 1000), [setFiles]);
 
   return { terms, files, tab: current, activeTerm, setTab, openTerminal, closeTerminal, openFiles, closeFiles, fileDirChanged };
 }