Ely Office: six offline-first desktop apps in Rust and GPUI

ElyDoc, ElyTable, ElyShow (LibreOfficeKit), ElyPDF (MuPDF), ElyTree (Git),
ElyMark (Milkdown and CodeMirror in CEF). ElyMail and ElyAgent follow.

apps/ely-agent/src/main.rs

@@ -0,0 +1,5 @@
+use ely_platform::AppId;
+
+fn main() {
+    ely_ui::run(AppId::Agent, ely_ui::blank);
+}