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/lib/lanes.js

@@ -736,10 +736,12 @@ function inferredDisplayStage(lane) {
   return lane.detected_stage;
 }
 
-/** The owner's username — the staff sidebar groups workspaces by it. */
-function ownerName(id) {
-  if (id == null) return null;
-  return db.prepare("SELECT username FROM users WHERE id = ?").get(id)?.username ?? null;
+/** The owner's username and display name — the staff sidebar groups
+ *  workspaces by owner and shows the display name when one is set. */
+function ownerNames(id) {
+  if (id == null) return { owner_name: null, owner_display_name: null };
+  const u = db.prepare("SELECT username, display_name FROM users WHERE id = ?").get(id);
+  return { owner_name: u?.username ?? null, owner_display_name: u?.display_name ?? null };
 }
 
 function lanePayload(lane, ageSec = null) {
@@ -755,7 +757,7 @@ function lanePayload(lane, ageSec = null) {
   delete row.instructions;
   return {
     ...row,
-    owner_name: ownerName(lane.owner_id),
+    ...ownerNames(lane.owner_id),
     pipeline_name: pipeline.name,
     pipeline_skill: pipeline.skill || "",
     pipeline_nodes: