feat: ON AIR status-bar badge + auto-updater UI (10-min check, progress)

ON AIR badge (bottom status bar, shown when live-status publishing is on): a
blinking red light + "On air" when a QSO was logged in the last 5 min, dim
"Offline" otherwise. Seeded at launch from LiveLastQSOAgeSec so it's right
immediately, flips online on qso:logged, expires via a 10s tick.

Auto-updater UI: the update check now also runs every 10 minutes, and the
update notification downloads and installs in-app — a live progress bar
(update:progress) then OpsLog restarts on the new build. Falls back to opening
the release page when there's no auto-download asset or on error (retry).
Regenerated bindings for DownloadAndApplyUpdate / LiveLastQSOAgeSec.

frontend/wailsjs/go/models.ts

@@ -2763,6 +2763,7 @@ export namespace main {
 	    latest: string;
 	    available: boolean;
 	    url: string;
+	    download_url: string;
 	
 	    static createFrom(source: any = {}) {
 	        return new UpdateInfo(source);
@@ -2774,6 +2775,7 @@ export namespace main {
 	        this.latest = source["latest"];
 	        this.available = source["available"];
 	        this.url = source["url"];
+	        this.download_url = source["download_url"];
 	    }
 	}
 	export class WKMacro {