replace leave lobby popup with custom popup (#4449)

## Description:
old:
<img width="1009" height="491" alt="image"
src="https://github.com/user-attachments/assets/0b95877c-dac7-4025-bdfa-62ab6879d208"
/>

new:
<img width="1017" height="561" alt="image"
src="https://github.com/user-attachments/assets/cfb49b31-eb46-4d64-bd9e-3f25bb7cd0fb"
/>




## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory

## Please put your Discord username so you can be contacted if a bug or
regression is found:

w.o.n

src/client/HostLobbyModal.ts

@@ -531,11 +531,9 @@ export class HostLobbyModal extends BaseModal {
         // Clear clipboard so the host doesn't accidentally share a dead link
         void navigator.clipboard.writeText("").catch(() => {});
       });
-    if (this.modalEl) {
-      this.modalEl.onClose = () => {
-        this.close();
-      };
-    }
+    // BaseModal.firstUpdated() owns modalEl.onClose so the o-modal close path
+    // (backdrop / close button) runs confirmBeforeClose(). Don't override it
+    // here — doing so would bypass the leave-lobby confirmation.
     this.loadNationCount();
   }
 
@@ -552,8 +550,8 @@ export class HostLobbyModal extends BaseModal {
     );
   }
 
-  public confirmBeforeClose(): boolean {
-    return confirm(translateText("host_modal.leave_confirmation"));
+  public confirmBeforeClose(): boolean | Promise<boolean> {
+    return this.confirmClose(translateText("host_modal.leave_confirmation"));
   }
 
   protected onClose(): void {

src/client/JoinLobbyModal.ts

@@ -336,9 +336,9 @@ export class JoinLobbyModal extends BaseModal {
     );
   }
 
-  public confirmBeforeClose(): boolean {
+  public confirmBeforeClose(): boolean | Promise<boolean> {
     if (!this.currentLobbyId) return true;
-    return confirm(translateText("host_modal.leave_confirmation"));
+    return this.confirmClose(translateText("host_modal.leave_confirmation"));
   }
 
   protected onClose(): void {

src/client/Navigation.ts

@@ -79,13 +79,30 @@ export function initNavigation() {
   window.showPage = showPage;
 
   // Use event delegation for navigation items (they may be inside Lit components)
-  document.addEventListener("click", (e) => {
+  document.addEventListener("click", async (e) => {
     const target = (e.target as HTMLElement).closest(
       ".nav-menu-item[data-page]",
     );
     if (target) {
       const pageId = (target as HTMLElement).dataset.page;
-      if (pageId) showPage(pageId);
+      if (!pageId) return;
+
+      // showPage() closes the currently visible modal, so respect its
+      // close-confirmation guard first (e.g. the leave-lobby prompt).
+      const visibleModal = document.querySelector(
+        ".page-content:not(.hidden)",
+      ) as any;
+      if (
+        visibleModal &&
+        typeof visibleModal.isOpen === "function" &&
+        visibleModal.isOpen() &&
+        typeof visibleModal.confirmBeforeClose === "function" &&
+        !(await visibleModal.confirmBeforeClose())
+      ) {
+        return;
+      }
+
+      showPage(pageId);
     }
   });
 
@@ -95,7 +112,7 @@ export function initNavigation() {
     const mainEl = document.querySelector("main");
 
     if (mainEl) {
-      mainEl.addEventListener("click", (e: Event) => {
+      mainEl.addEventListener("click", async (e: Event) => {
         const target = e.target as HTMLElement;
         const isPlayPageHidden = document
           .getElementById("page-play")
@@ -118,7 +135,7 @@ export function initNavigation() {
               // Check confirmation guard before closing
               if (
                 typeof openModal.confirmBeforeClose === "function" &&
-                !openModal.confirmBeforeClose()
+                !(await openModal.confirmBeforeClose())
               ) {
                 return;
               }

src/client/components/BaseModal.ts

@@ -3,6 +3,7 @@ import { property, query, state } from "lit/decorators.js";
 import { modalRouter } from "../ModalRouter";
 import "./baseComponents/Modal";
 import type { OModalTab } from "./baseComponents/Modal";
+import "./ConfirmDialog";
 
 /**
  * Static-ish configuration for the <o-modal> shell.
@@ -39,6 +40,12 @@ export abstract class BaseModal extends LitElement {
   @state() protected activeTab = "";
   @property({ type: Boolean }) inline = false;
 
+  // Pending close confirmation; when set, renders the inline confirm dialog.
+  @state() private closeConfirm: {
+    message: string;
+    resolve: (ok: boolean) => void;
+  } | null = null;
+
   // Re-entrancy guard: showPage() (for inline modals) re-invokes .open()
   // with no args after we call it. We must not re-run onOpen(undefined)
   // from that nested call, which would clobber state set by the outer call.
@@ -91,12 +98,30 @@ export abstract class BaseModal extends LitElement {
 
   /**
    * Guard called before closing via Escape key or click-outside.
-   * Return false to prevent the modal from closing.
+   * Return false (or a promise resolving false) to prevent closing.
    */
-  public confirmBeforeClose(): boolean {
+  public confirmBeforeClose(): boolean | Promise<boolean> {
     return true;
   }
 
+  /**
+   * Show a styled confirm dialog and resolve to the user's choice. Call from
+   * confirmBeforeClose() to gate closing behind a confirm/cancel prompt.
+   */
+  protected confirmClose(message: string): Promise<boolean> {
+    // Don't stack a second prompt if one is already open.
+    if (this.closeConfirm) return Promise.resolve(false);
+    return new Promise((resolve) => {
+      this.closeConfirm = { message, resolve };
+    });
+  }
+
+  private settleCloseConfirm(ok: boolean) {
+    const pending = this.closeConfirm;
+    this.closeConfirm = null;
+    pending?.resolve(ok);
+  }
+
   // ---- Rendering ----
 
   createRenderRoot() {
@@ -133,6 +158,14 @@ export abstract class BaseModal extends LitElement {
         ${headerSlot ? html`<div slot="header">${headerSlot}</div>` : null}
         ${body}
       </o-modal>
+      ${this.closeConfirm
+        ? html`<confirm-dialog
+            .message=${this.closeConfirm.message}
+            variant="warning"
+            @confirm=${() => this.settleCloseConfirm(true)}
+            @cancel=${() => this.settleCloseConfirm(false)}
+          ></confirm-dialog>`
+        : null}
     `;
   }
 
@@ -199,6 +232,9 @@ export abstract class BaseModal extends LitElement {
   }
 
   public close(args?: Record<string, unknown>): void {
+    // If closing was triggered elsewhere while a confirm prompt is pending,
+    // dismiss it (removes the dialog and resolves the awaiting guard as false).
+    this.settleCloseConfirm(false);
     this.unregisterEscapeHandler();
     this.onClose(args);
 
@@ -234,9 +270,13 @@ export abstract class BaseModal extends LitElement {
 
   protected firstUpdated(): void {
     if (this.modalEl) {
-      this.modalEl.onClose = () => {
+      this.modalEl.onClose = async () => {
         if (this.isModalOpen) {
-          if (!this.confirmBeforeClose()) {
+          const confirmed = await this.confirmBeforeClose();
+          // Bail if a parallel close() settled things while we awaited —
+          // otherwise we'd re-open an already-closed modal.
+          if (!this.isModalOpen) return;
+          if (!confirmed) {
             // Re-open the underlying o-modal since it already closed itself
             this.modalEl?.open();
             return;
@@ -248,14 +288,17 @@ export abstract class BaseModal extends LitElement {
   }
 
   disconnectedCallback() {
+    this.settleCloseConfirm(false);
     this.unregisterEscapeHandler();
     super.disconnectedCallback();
   }
 
-  private handleKeyDown = (e: KeyboardEvent) => {
+  private handleKeyDown = async (e: KeyboardEvent) => {
     if (e.key === "Escape" && this.isModalOpen) {
       e.preventDefault();
-      if (!this.confirmBeforeClose()) {
+      const confirmed = await this.confirmBeforeClose();
+      // Bail if a parallel close() already closed us while we awaited.
+      if (!confirmed || !this.isModalOpen) {
         return;
       }
       this.close();