feat: v2.7.6 — edit users in one form, Settings → Account, display names, copy over plain HTTP

- Users page: one Edit user form (display name, email, role, active, a new or
  generated password, workspaces given or taken back, sign out everywhere),
  validated as a whole before anything is written (PATCH /api/users/:id,
  GET /api/users/:id); users.display_name/email added migration-safe.
- Settings → Account for every signed-in user: profile, own password (the
  current one required, this login kept), sign out other devices
  (/api/me/account, /api/me/password, /api/me/sign-out-others; login cookie
  only, never a pane token).
- Display names wherever a person is named (sidebar, workspace owner groups,
  Users page and audit log); owner_display_name / reader_display additive.
- Users page: admins add and remove Claude/Codex pool accounts.
- Folder browser: an admin with their own Linux account opens in their home;
  the "Server folder" tick opens the host's (never remembered).
- AI Proxy: "Config 9router" beside Add profile when 9router is installed,
  opened on the dashboard's own host (GET /api/ai-proxies/9router).
- Terminal: a tmux selection reaches the clipboard over plain HTTP too
  (writeClipboard's textarea fallback, focus handed back).
- Chat: a file the session touched outside the workspace previews
  (GET /api/sessions/:id/file).
- install-system: `!requiretty` only when visudo accepts it (sudo-rs on
  Ubuntu 25.10+ rejects the setting).
- openapi.yaml regenerated; docs (API, SERVER-MODE, LANES) updated.

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

client/src/components/AuthGate.tsx

@@ -6,7 +6,8 @@
  * when this browser last saw local mode (`agenthub.authMode`); in server mode it renders the login page until
  * someone logs in, and again whenever a request answers 401 `EAUTH`
  * (`AUTH_REQUIRED_EVENT`). Logging out unmounts the app, so no page keeps the
- * previous user's data. `useAuth()` gives the sidebar the user and `logout`;
+ * previous user's data. `useAuth()` gives the sidebar the user, `logout`, and
+ * `updateUser` (Settings → Account's saved display name shows at once);
  * `usePermissions()` says what that user's role may do, so pages hide the rest.
  * Once an account is known (local mode is one), its own UI preferences are
  * loaded into this browser (`lib/userPrefs.ts`).
@@ -16,6 +17,7 @@
 
 import {
   createContext,
+  useCallback,
   useContext,
   useEffect,
   useLayoutEffect,
@@ -30,9 +32,17 @@ import { applySystemTheme } from "../hooks/useTheme";
 import { api, AUTH_REQUIRED_EVENT, type AuthState, type AuthUser } from "../lib/api";
 import { hydrate } from "../lib/userPrefs";
 
-type AuthValue = { state: AuthState; logout: () => Promise<void> };
+type AuthValue = {
+  state: AuthState;
+  logout: () => Promise<void>;
+  updateUser: (patch: Partial<AuthUser>) => void;
+};
 
-const AuthContext = createContext<AuthValue>({ state: { mode: "local" }, logout: async () => {} });
+const AuthContext = createContext<AuthValue>({
+  state: { mode: "local" },
+  logout: async () => {},
+  updateUser: () => {},
+});
 
 /** The current login; `{mode: "local"}` outside server mode (and in tests). */
 export const useAuth = () => useContext(AuthContext);
@@ -134,6 +144,15 @@ export function AuthGate({ children }: { children: ReactNode }) {
     if (account) void hydrate();
   }, [account]);
 
+  // Stable, so a page may list it as an effect dependency.
+  const updateUser = useCallback(
+    (patch: Partial<AuthUser>) =>
+      setState((s) =>
+        s && s.mode === "server" && s.user ? { ...s, user: { ...s.user, ...patch } } : s
+      ),
+    []
+  );
+
   if (!state) return null;
   if (state.mode === "server" && !state.user) {
     return <LoginPage onLoggedIn={(user) => setState({ mode: "server", user })} />;
@@ -142,7 +161,9 @@ export function AuthGate({ children }: { children: ReactNode }) {
     await api.auth.logout().catch(() => {});
     setState({ mode: "server", user: null });
   };
-  return <AuthContext.Provider value={{ state, logout }}>{children}</AuthContext.Provider>;
+  return (
+    <AuthContext.Provider value={{ state, logout, updateUser }}>{children}</AuthContext.Provider>
+  );
 }
 
 function LoginPage({ onLoggedIn }: { onLoggedIn: (user: AuthUser) => void }) {