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>

server/routes/ai-proxies.js

@@ -22,14 +22,20 @@
  * `GET /:name` — a route that returned one profile in full would be the one
  * way an API key could leave this process.
  *
+ * `GET /9router` only says whether a `9router` binary is on the server's PATH,
+ * so the page can offer a link to its own config UI; it never runs it.
+ *
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
+const path = require("node:path");
 const express = require("express");
 
 const proxies = require("../lib/ai-proxies");
 const { refreshProfileFiles, removeProfileFiles } = require("../lib/proxy-apply");
 const { sameOriginGuard } = require("../lib/same-origin");
+const { which } = require("../lib/ai-tools");
+const { shellPath } = require("../lib/shell-path");
 
 const router = express.Router();
 
@@ -74,6 +80,13 @@ router.get("/", (req, res) => {
   }
 });
 
+// GET /api/ai-proxies/9router — is 9router installed here? `{ installed }`.
+// A file lookup on PATH only; nothing is spawned.
+router.get("/9router", (_req, res) => {
+  const pathStr = [shellPath(), process.env.PATH].filter(Boolean).join(path.delimiter);
+  res.json({ installed: Boolean(which("9router", pathStr)) });
+});
+
 // POST /api/ai-proxies — body: { label, baseUrl, apiKey?, model, models?,
 // behavesAs?, scope? }. `scope` is "shared" (an admin's default) or "personal"
 // (a member's only choice); local mode has no user and always writes shared.