feat: add opt-out toggle for prestige bot announcements

Adds enablePrestigeAnnouncements to ProfileSettings (defaults to true).
The prestige route now checks this setting before posting the Discord
webhook, and the edit profile modal exposes a toggle in the Sounds &
Notifications section so players can opt out.

Closes #169

apps/web/src/components/game/editProfileModal.tsx

@@ -225,6 +225,10 @@ const EditProfileModal = ({
     void handleNotificationsEnable();
   }
 
+  function handlePrestigeAnnouncementsToggle(): void {
+    toggleSetting("enablePrestigeAnnouncements");
+  }
+
   const isSaveDisabled = saving || characterName.trim() === "";
 
   let saveLabel = "Save Profile";
@@ -417,6 +421,23 @@ const EditProfileModal = ({
                   }
                 </span>
               </button>
+              <button
+                className={`stat-toggle-btn ${
+                  profileSettings.enablePrestigeAnnouncements
+                    ? "stat-toggle-on"
+                    : "stat-toggle-off"
+                }`}
+                onClick={handlePrestigeAnnouncementsToggle}
+                type="button"
+              >
+                <span>{"⭐ Prestige Bot Announcements"}</span>
+                <span className="stat-toggle-indicator">
+                  {profileSettings.enablePrestigeAnnouncements
+                    ? "✓ On"
+                    : "Off"
+                  }
+                </span>
+              </button>
             </div>
 
             <div className="edit-profile-section">