diff --git a/platformio.ini b/platformio.ini
index 96ec996..ddd4cb9 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -126,6 +126,13 @@ build_flags =
     -DPIN_PWR=1
     -DPANEL_ID=\"waveshare-13.3-spectra6\"
     -DBOARD_HAS_PSRAM
+    ; Route Serial through the S3's native USB-CDC. Without this the default
+    ; arduino-esp32 routing sends Serial to UART0, whose pins aren't wired to
+    ; either USB endpoint on the 13.3E6 board — making firmware logs invisible
+    ; over USB and forcing reliance on server-side telemetry alone. The CDC
+    ; endpoint enumerates as the "Espressif USB JTAG serial debug unit" ACM
+    ; port; it disappears when the chip deep-sleeps and re-enumerates on wake.
+    -DARDUINO_USB_CDC_ON_BOOT=1
 lib_deps =
     ricmoo/QRCode@^0.0.1
 
diff --git a/src/operation.h b/src/operation.h
index 17f4f31..a7cfe14 100644
--- a/src/operation.h
+++ b/src/operation.h
@@ -160,6 +160,19 @@ void normal_operation_impl(const String& mac, HTTP& http, const String& url, Pre
         http.addHeader("X-Just-Provisioned", "1");
     }
 
+    // Recovery handshake: drawNeeded survives a power-loss-during-draw
+    // because we set it before kicking the e-ink refresh and only clear
+    // it after the panel finishes. Telling the server about it lets it
+    // suppress rotation advancement (including the X-Boot-Reason: cold
+    // force-resync) so we get the SAME image back and can repaint it
+    // from the cached /img.bin, instead of chasing a fresh image every
+    // time a draw resets. Without this, cold-boot rotation defeats the
+    // 304-with-drawNeeded recovery branch and the device churns through
+    // images, leaving torn frames on the panel.
+    if (drawNeeded) {
+        http.addHeader("X-Draw-Pending", "1");
+    }
+
     const char* collectHeaders[] = { "X-Interval-Ms", "X-Image-Id", "X-Image-Sha256", "X-Claimed" };
     http.collectHeaders(collectHeaders, 4);
     int code = http.GET();
diff --git a/test/test_normal_operation/test_main.cpp b/test/test_normal_operation/test_main.cpp
index 21bb2dc..3a17cee 100644
--- a/test/test_normal_operation/test_main.cpp
+++ b/test/test_normal_operation/test_main.cpp
@@ -608,6 +608,41 @@ void test_fw_bootstrap_loop_iterates_when_no_image() {
     TEST_ASSERT_TRUE(g_deep_sleep_started);
 }
 
+// FW-DRAWPENDING-A: when drawNeeded is set in NVS at boot, the poll must
+// carry X-Draw-Pending: 1. Server uses this to suppress rotation advancement
+// (incl. cold-boot force-resync) so the device gets the SAME image back and
+// can retry the interrupted draw from the cached /img.bin. Without the
+// header, cold-boot rotation defeats the 304-with-drawNeeded recovery branch.
+void test_fw_draw_pending_header_when_draw_needed_set() {
+    prefs.begin(NVS_NAMESPACE, false);
+    prefs.putInt(NVS_KEY_DRAW_NEEDED, 1);
+    prefs.putInt(NVS_KEY_SCHEMA_V, NVS_SCHEMA_VERSION);  // skip migration noise
+    prefs.end();
+    g_http_response_headers["X-Image-Id"] = "1";
+
+    normal_operation_impl(String("mac"), http, String("url"), prefs);
+
+    TEST_ASSERT_TRUE_MESSAGE(
+        g_http_request_headers.find("X-Draw-Pending") != g_http_request_headers.end(),
+        "X-Draw-Pending header must be present when drawNeeded is set");
+    TEST_ASSERT_EQUAL_STRING("1", g_http_request_headers["X-Draw-Pending"].c_str());
+}
+
+// FW-DRAWPENDING-B: in the normal case (drawNeeded == 0), the header is
+// absent. The server treats absence as "device is happy, you may rotate."
+void test_fw_draw_pending_header_absent_when_no_draw_needed() {
+    prefs.begin(NVS_NAMESPACE, false);
+    prefs.putInt(NVS_KEY_SCHEMA_V, NVS_SCHEMA_VERSION);
+    prefs.end();
+    g_http_response_headers["X-Image-Id"] = "1";
+
+    normal_operation_impl(String("mac"), http, String("url"), prefs);
+
+    TEST_ASSERT_TRUE_MESSAGE(
+        g_http_request_headers.find("X-Draw-Pending") == g_http_request_headers.end(),
+        "X-Draw-Pending header must be absent when drawNeeded is clear");
+}
+
 // FW-12/13: AP SSID derivation via ap_ssid_from_mac()
 void test_fw12_ap_ssid_from_mac_aabbcc() {
     String ssid = ap_ssid_from_mac(String("AA:BB:CC:DD:EE:FF"));
@@ -661,5 +696,7 @@ int main(int argc, char** argv) {
     RUN_TEST(test_fw_panel_id_header_value_matches_macro);
     RUN_TEST(test_fw_bootstrap_loop_exits_after_deep_sleep);
     RUN_TEST(test_fw_bootstrap_loop_iterates_when_no_image);
+    RUN_TEST(test_fw_draw_pending_header_when_draw_needed_set);
+    RUN_TEST(test_fw_draw_pending_header_absent_when_no_draw_needed);
     return UNITY_END();
 }