feat(fusion_clock): camera capture on NFC kiosk

Replace camera stub with real getUserMedia + canvas capture. Setup button
now starts NFC reader and camera together; camera failure is non-fatal when
photo is not required.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

fusion_clock/static/src/js/fusion_clock_nfc_kiosk.js

@@ -177,10 +177,33 @@
     }
 
     // ──────────────────────────────────────────────────────────────
-    // Camera capture (real implementation in Task 17, stub for now)
+    // Camera
     // ──────────────────────────────────────────────────────────────
+    let cameraStream = null;
+    const videoEl = document.getElementById("nfc_camera_feed");
+    const canvasEl = document.getElementById("nfc_camera_canvas");
+
+    async function startCamera() {
+        if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
+            throw new Error("Camera not supported on this browser/device.");
+        }
+        cameraStream = await navigator.mediaDevices.getUserMedia({
+            video: { facingMode: "user", width: { ideal: 640 }, height: { ideal: 480 } },
+            audio: false,
+        });
+        videoEl.srcObject = cameraStream;
+        await videoEl.play();
+    }
+
     async function capturePhoto() {
-        return ""; // overridden in Task 17
+        if (!videoEl || !canvasEl || !videoEl.videoWidth) return "";
+        const w = videoEl.videoWidth;
+        const h = videoEl.videoHeight;
+        canvasEl.width = w;
+        canvasEl.height = h;
+        const ctx = canvasEl.getContext("2d");
+        ctx.drawImage(videoEl, 0, 0, w, h);
+        return canvasEl.toDataURL("image/jpeg", 0.7);
     }
 
     // ──────────────────────────────────────────────────────────────
@@ -191,6 +214,12 @@
         setupBtn.addEventListener("click", async () => {
             try {
                 await startNfcReader();
+                try {
+                    await startCamera();
+                } catch (camErr) {
+                    if (photoRequired) throw camErr;
+                    console.warn("[nfc-kiosk] camera unavailable, continuing (photo not required)", camErr);
+                }
                 setState(STATE.IDLE);
             } catch (e) {
                 stateContainer.innerHTML = `