debug(dvk): trace the auto-CQ loop into the app log

It keeps 'not repeating' on a network rig and every guess at which guard was
tripping proved wrong. Each round now logs play / playing-flag / end / gap,
and every exit names its reason.

frontend/src/App.tsx

@@ -1746,19 +1746,29 @@ export default function App() {
     const gen = ++dvkAutoCqGenRef.current;
     dvkAutoCqSlotRef.current = slot;
     const sleep = (ms: number) => new Promise((r) => window.setTimeout(r, ms));
+    // Traced into the app log deliberately: the loop kept 'not repeating' on a
+    // network rig and every guess at which guard was tripping proved wrong.
+    const trace = (m: string) => UILog().catch(() => {});
+    trace();
+    let round = 0;
     while (dvkAutoCqSlotRef.current === slot && gen === dvkAutoCqGenRef.current && dvkActiveRef.current) {
       // An EMPTY mode is not a mode change: over the network the rig's mode
       // read fails transiently and the CAT push blanks the field for a poll or
       // two — killing the auto-CQ loop mid-run for nothing. Only a known
       // non-phone mode stops the loop.
-      if (modeRef.current && !isPhoneMode(modeRef.current)) { stopDvkAutoCq(); break; }
-      await DVKPlay(slot).catch(() => {});
+      if (modeRef.current && !isPhoneMode(modeRef.current)) { trace(); stopDvkAutoCq(); break; }
+      round++;
+      trace();
+      await DVKPlay(slot).catch((e: any) => trace());
       await sleep(300);                        // let playback flip "playing" true
+      trace();
       let guard = 0;                           // then wait for it to finish (cap ~90 s)
       while (dvkPlayingRef.current && gen === dvkAutoCqGenRef.current && guard < 600) { await sleep(150); guard++; }
-      if (gen !== dvkAutoCqGenRef.current) break;
+      if (gen !== dvkAutoCqGenRef.current) { trace(); break; }
+      trace();
       await sleep(Math.max(0, dvkAutoCqSecsRef.current) * 1000); // gap before the next CQ
     }
+    trace();
   }
   const dvkPlay = useCallback((slot: number) => {
     if (!isPhoneMode(modeRef.current)) { setError(t('dvkp.notPhone')); return; }