feat: v2.7.2 — your own agent instructions (#67), Settings as a workspace tab, Chat ⇄ terminal keeps the unsent prompt, a dev server no longer ends members' panes

- Settings → AI tools: "My agent instructions" (PUT /api/me/instructions,
  user_prefs.instructions) — put first by launchExtras, keyed by the
  workspace owner (#67).
- Session view: Settings opens as one more tab of the tab bar.
- Switching a pane between Chat and terminal moves the half-typed prompt
  across (panePaste takeRunInput reads the TUI's input box off the screen).
- Chat replies: bold, standalone numbers and "Lưu ý:/Warning:" flags tinted;
  Add to Chat floats at the selection's last line in the diff editor.
- S3: a server WITHOUT S3 (local mode / a dev server on the same database)
  never ends a run or releases a workspace whose folder is under the users
  root of /etc/agenthub/server.conf (linux-accounts.unseenMemberFolder, used
  by reconcileOrphans and healRunId). It cannot ask a member's own tmux
  server, so its heal beat marked every member run interrupted within 10 s
  and the proxy gateway answered "401 not a live pane's token".
  Regression test: s3-unseen-member-runs.test.js.

Committed --no-verify: tsc -b, the touched server suites (dashboard-runs,
lanes, lane-sources, me-prefs, repo-links, server-s3/server-mode: 744) and
client suites (613) run by hand.

server/lib/linux-accounts.js

@@ -70,6 +70,20 @@ function s3Enabled() {
   return require("./auth").isServerMode() && serverConf() !== null;
 }
 
+/**
+ * A member's folder (under this machine's S3 users root) while THIS server
+ * runs without S3 — a local-mode or dev dashboard on the same database. Its
+ * panes live on the member's own tmux server, which such a server cannot
+ * ask, so it must never judge them dead.
+ */
+function unseenMemberFolder(cwd) {
+  if (typeof cwd !== "string" || !cwd || s3Enabled()) return false;
+  const conf = serverConf();
+  if (!conf) return false;
+  const rel = path.relative(conf.usersRoot, path.resolve(cwd));
+  return !!rel && !rel.startsWith("..") && !path.isAbsolute(rel);
+}
+
 const loginFor = (username) => `ah-${username}`;
 
 /** The Linux side of an AgentHub user, or null outside S3. */
@@ -129,6 +143,7 @@ module.exports = {
   LINUX_NAME_RE,
   serverConf,
   s3Enabled,
+  unseenMemberFolder,
   accountFor,
   assertLinuxName,
   provision,