sketch-app-shell: nav to /messages/ on sessionEnd

Fixes https://github.com/boldsoftware/bold/issues/457
diff --git a/webui/src/web-components/sketch-app-shell.ts b/webui/src/web-components/sketch-app-shell.ts
index facbba2..1c12b2c 100644
--- a/webui/src/web-components/sketch-app-shell.ts
+++ b/webui/src/web-components/sketch-app-shell.ts
@@ -5,6 +5,18 @@
 
 @customElement("sketch-app-shell")
 export class SketchAppShell extends SketchAppShellBase {
+  connectedCallback(): void {
+    super.connectedCallback();
+
+    this.dataManager.addEventListener("sessionEnded", () => {
+      this.handleSessionEnded();
+    });
+  }
+
+  async handleSessionEnded() {
+    await this.navigateToMessagesArchiveView();
+  }
+
   render() {
     return html`
       <!-- Main container: flex column, full height, system font, hidden overflow-x -->