viewer: make /api/phone poll configurable (default off)

src/phone_harness/config.py

@@ -67,3 +67,9 @@ def get(key: str, default: str | None = None) -> str | None:
 MJPEG_FPS = int(get("MJPEG_FPS", "60") or "60")
 MJPEG_QUALITY = int(get("MJPEG_QUALITY", "70") or "70")
 MJPEG_SCALE = int(get("MJPEG_SCALE", "50") or "50")
+
+# Viewer poll for /api/phone: seconds between polls. 0 disables the periodic
+# poll (viewer will still call loadPhone() on load). Default 0 avoids the
+# viewer accidentally triggering a WDA wedge; operators can enable it in
+# .env with VIEWER_PHONE_POLL_SECONDS=10 for a 10s poll.
+VIEWER_PHONE_POLL_SECONDS = float(get("VIEWER_PHONE_POLL_SECONDS", "0") or "0")

src/phone_harness/viewer.html

@@ -934,7 +934,19 @@ <h2 class="sec">Phone</h2>
   setInterval(loadApproval, 1000);  // a blocked send must surface fast
   loadApproval();
   loadGate();
-  setInterval(loadPhone, 10000);
+  // Configure periodic polling of /api/phone from server side. Server may
+  // return 0 to disable the periodic poll (recommended when a device is
+  // susceptible to WDA heavy-tail wedges). The viewer still calls loadPhone
+  // once on load so the UI is populated.
+  fetch('/api/config').then(r => r.json()).then(cfg => {
+    const s = Number(cfg.phone_poll_seconds) || 0;
+    if (s > 0) {
+      setInterval(loadPhone, Math.max(1000, Math.round(s * 1000)));
+    }
+  }).catch(() => {
+    // Fallback: keep the previous 10s poll if config cannot be read.
+    setInterval(loadPhone, 10000);
+  });
   // Both clamps are measured, so both are wrong the moment the window changes
   // size. Re-fit on resize only — never on a poll, or the column would thrash.
   let refit;
@@ -1118,6 +1130,12 @@ <h2 class="sec">Phone</h2>
 // ---- keyboard: type on your keyboard, characters go to the phone -----------
 let keyBuf = '';
 let keyBusy = false;
+const ARROW_KEYS = {
+  ArrowLeft: '\uE012', ArrowRight: '\uE014',
+  ArrowUp: '\uE013', ArrowDown: '\uE015'
+};
+let arrowBuf = [];
+let arrowBusy = false;
 async function flushKeys() {
   if (keyBusy || !keyBuf) return;
   const text = keyBuf; keyBuf = '';
@@ -1130,6 +1148,20 @@ <h2 class="sec">Phone</h2>
     if (keyBuf) flushKeys();   // send what queued up while we were busy
   }
 }
+async function sendArrowKey(key) {
+  arrowBuf.push(key);
+  if (arrowBusy) return;
+  arrowBusy = true;
+  try {
+    while (arrowBuf.length) {
+      const next = arrowBuf.shift();
+      await fetch('/api/key', {method:'POST', headers:JSON_HDR,
+                                body: JSON.stringify({key: next})});
+    }
+  } finally {
+    arrowBusy = false;
+  }
+}
 window.addEventListener('paste', async (ev) => {
   if (ovOpen) return;
   if (!inputEnabled || phoneBusy()) return;
@@ -1168,6 +1200,12 @@ <h2 class="sec">Phone</h2>
   }
   if (ev.ctrlKey || ev.metaKey || ev.altKey) return;   // keep browser shortcuts
   if (phoneBusy()) { ev.preventDefault(); return; }    // keys aimed at the pre-action screen
+  const arrow = ARROW_KEYS[ev.key];
+  if (arrow) {
+    ev.preventDefault();
+    sendArrowKey(arrow);
+    return;
+  }
   let ch = null;
   if (ev.key === 'Enter') ch = '\n';
   else if (ev.key === 'Backspace') ch = '\b';

src/phone_harness/viewer.py

@@ -563,6 +563,17 @@ def do_GET(self):  # noqa: vulture
                         pass
                 _LAST_PHONE = info
                 self._json(info)
+            elif path == "/api/config":
+                # Viewer configuration (client-visible). phone_poll_seconds is
+                # the interval in seconds for the viewer to poll /api/phone.
+                # 0 means disabled; the viewer still calls loadPhone() once on
+                # load so the UI shows current state.
+                try:
+                    self._json(
+                        {"phone_poll_seconds": float(config.VIEWER_PHONE_POLL_SECONDS)}
+                    )
+                except Exception:
+                    self._json({"phone_poll_seconds": 0.0})
             elif path == "/api/doctor":
                 global _LAST_DOCTOR
                 if _ACTION_LOCK.locked() and _LAST_DOCTOR is not None:
@@ -654,6 +665,10 @@ def do_POST(self):  # noqa: vulture
                 with _action_slot():
                     self.client.type_text(str(payload.get("text", "")))
                 self._json({"ok": True})
+            elif path == "/api/key":
+                with _action_slot():
+                    self.client.key_press(str(payload["key"]))
+                self._json({"ok": True})
             elif path == "/api/clipboard":
                 text = str(payload.get("text", payload.get("content", "")))
                 try: