fix(windows): merge taskbar icon (AUMID) + focus window on notification click

Taskbar showed two icons because the AppUserModelID was (a) set too late — after
the main window was built, so its taskbar button grouped under a mismatched
implicit AUMID — and (b) valued 'LotusGuild.LotusChat', which differs from the
bundle identifier 'org.lotusguild.lotus-chat' that Tauri's NSIS installer stamps
on its shortcuts. Fix both: set the AUMID at the top of run() before the window
is built (new set_process_aumid, split out of ensure_app_user_model_id), and
align the constant to the bundle identifier so the running window and a pinned
installer shortcut group together.

Notification click didn't raise the window: add a focus_main_window command
(reuses show_main) for the web/service-worker path, and call show_main directly
in the rich-toast Activated body-click handler.

Note: existing users who pinned the old mis-grouped icon may need to re-pin once.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src-tauri/src/native/toast.rs

@@ -186,7 +186,13 @@ fn show_windows_toast(
                 .to_string();
                 super::emit_to_web(&app_activated, "lotus-notification-reply", &payload);
             } else {
-                // Plain body click: forward the launch path so the web routes to it.
+                // Plain body click: raise the window to the foreground (the
+                // "foreground" activationType is unreliable for an unpackaged app,
+                // so do it explicitly), then forward the launch path so the web
+                // routes to the room. `show_main` is the shared tray/deep-link
+                // helper. Not done for the reply branch — an inline quick-reply
+                // shouldn't yank the window forward.
+                crate::show_main(&app_activated);
                 let payload = serde_json::json!({
                     "path": path_owned.as_deref(),
                 })