Add ATC Team chat, soft identity, and update Present decks.

Ship team/DM chat with files, avatars, unread alerts, and a first-open identity gate (including Guest); fold Team into Ops desk; clarify Datacenter Engineer vs "Data Plumbers" FDE roles; refresh Present story/tech slides to match.

Co-authored-by: Cursor <cursoragent@cursor.com>

ui/reports.js

@@ -77,7 +77,7 @@
     const drawer = $("#reports-drawer");
     const scrim = $("#scrim");
     if (!drawer) return;
-    ["#chat-drawer", "#ops-drawer", "#ai-drawer", "#network-drawer", "#console-drawer"].forEach((id) => {
+    ["#chat-drawer", "#ops-drawer", "#ai-drawer", "#network-drawer", "#console-drawer", "#team-drawer"].forEach((id) => {
       const el = $(id);
       if (el) {
         el.classList.remove("open");