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/db.js

@@ -1815,6 +1815,15 @@ try {
     `);
   }
 }
+// An account's own display name and email (the Users page's Edit user and
+// Settings → Account). Additive; after the rebuild above, which predates them.
+for (const col of ["display_name", "email"]) {
+  try {
+    db.prepare(`SELECT ${col} FROM users LIMIT 1`).get();
+  } catch {
+    db.prepare(`ALTER TABLE users ADD COLUMN ${col} TEXT`).run();
+  }
+}
 
 migrationLock.exec("COMMIT");
 migrationLock.close();