feat(fusion_clock): NFC kiosk Wake Lock to keep screen on while active

fusion_clock/static/src/js/fusion_clock_nfc_kiosk.js

@@ -410,6 +410,43 @@
         return canvasEl.toDataURL("image/jpeg", 0.7);
     }
 
+    // ──────────────────────────────────────────────────────────────
+    // Wake Lock — keeps the screen on while the kiosk page is active.
+    // Released automatically on tab close/navigation; re-acquired on
+    // visibilitychange when the page comes back to the foreground.
+    // ──────────────────────────────────────────────────────────────
+    let wakeLock = null;
+
+    async function acquireWakeLock() {
+        if (!("wakeLock" in navigator)) {
+            debugLog("wakeLock: API not supported on this browser");
+            return;
+        }
+        if (wakeLock) {
+            debugLog("wakeLock: already held, skipping");
+            return;
+        }
+        try {
+            wakeLock = await navigator.wakeLock.request("screen");
+            debugLog("wakeLock: acquired ✓ (screen will stay on)");
+            wakeLock.addEventListener("release", () => {
+                debugLog("wakeLock: released by browser/OS");
+                wakeLock = null;
+            });
+        } catch (e) {
+            debugLog("wakeLock: request failed: " + (e && e.message));
+        }
+    }
+
+    document.addEventListener("visibilitychange", async () => {
+        if (document.visibilityState === "visible") {
+            debugLog("visibility: visible — re-acquiring wakeLock");
+            await acquireWakeLock();
+        } else {
+            debugLog("visibility: " + document.visibilityState);
+        }
+    });
+
     // ──────────────────────────────────────────────────────────────
     // Setup wizard activation
     // ──────────────────────────────────────────────────────────────
@@ -428,6 +465,7 @@
                     if (photoRequired) throw camErr;
                     console.warn("[nfc-kiosk] camera unavailable, continuing (photo not required)", camErr);
                 }
+                await acquireWakeLock();
                 setState(STATE.IDLE);
             } catch (e) {
                 stateContainer.innerHTML = `