diff --git a/.github/workflows/run-unit-tests.yml b/.github/workflows/run-unit-tests.yml
index e503b2218..01d918f08 100644
--- a/.github/workflows/run-unit-tests.yml
+++ b/.github/workflows/run-unit-tests.yml
@@ -801,6 +801,7 @@ jobs:
           python3 -B test/test_companion_pairing_display.py
           python3 -B test/test_companion_identity_startup.py
           python3 -B test/test_startup_screen.py
+          python3 -B test/test_ui_startup_windows.py -v
           node test/test_notification_builder.js
           python3 -B test/test_notification_settings.py
           python3 -B test/test_notification_led_ownership.py -v
diff --git a/examples/companion_radio/ui-new/UITask.cpp b/examples/companion_radio/ui-new/UITask.cpp
index 2e1d3d1dd..a2075426e 100644
--- a/examples/companion_radio/ui-new/UITask.cpp
+++ b/examples/companion_radio/ui-new/UITask.cpp
@@ -1968,6 +1968,7 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, CompanionNode
 #endif
 
   ui_started_at = millis();
+  _startup_complete = false;
   next_batt_chck = _next_refresh = ui_started_at;
   _alert[0] = 0;
   _alert_expiry = 0;
@@ -2275,6 +2276,10 @@ bool UITask::isButtonGesturePending() const {
 }
 
 void UITask::loop() {
+  // Observe startup expiry even while display/Morse/input defers rendering.
+  if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) >= 8000u) {
+    _startup_complete = true;
+  }
   const bool morse_timing = mesh::morseTimingActive(&radio_driver);
   serviceWiFiToggleButton();
   servicePairingState();
@@ -2624,7 +2629,7 @@ char UITask::handleLongPress(char c) {
     return c;
   }
 #endif
-  if (millis() - ui_started_at < 8000) {   // long press in first 8 seconds since startup -> CLI/rescue
+  if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) < 8000u) { // early-boot CLI/rescue only
     the_mesh.enterCLIRescue();
     c = 0;   // consume event
   }
diff --git a/examples/companion_radio/ui-new/UITask.h b/examples/companion_radio/ui-new/UITask.h
index ad0bab61c..ba80054dd 100644
--- a/examples/companion_radio/ui-new/UITask.h
+++ b/examples/companion_radio/ui-new/UITask.h
@@ -42,6 +42,7 @@ class UITask : public AbstractUITask {
   uint32_t _next_refresh;
   unsigned long _pairing_screen_until;
   bool _deferred_msg_preview;
+  bool _startup_complete = false;
   CompanionNodePrefs* _node_prefs;
   char _alert[80];
   uint32_t _alert_expiry;
diff --git a/examples/companion_radio/ui-orig/UITask.cpp b/examples/companion_radio/ui-orig/UITask.cpp
index 9ef7432aa..fd66182bc 100644
--- a/examples/companion_radio/ui-orig/UITask.cpp
+++ b/examples/companion_radio/ui-orig/UITask.cpp
@@ -159,6 +159,7 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, CompanionNode
   _userButtonAnalog->onAnyPress([this]() { handleButtonAnyPress(); });
 #endif
   ui_started_at = millis();
+  _startup_complete = false;
   _next_refresh = ui_started_at;
 }
 
@@ -352,7 +353,8 @@ void UITask::renderCurrScreen() {
     _display->print(tmp);
 #endif
     _display->setColor(UIColor::secondary_txt); // last color will be kept on T114
-  } else if (!pairing_screen_active && (millis() - ui_started_at) < BOOT_SCREEN_MILLIS) { // boot screen
+  } else if (!pairing_screen_active && !_startup_complete
+      && static_cast<uint32_t>(millis() - ui_started_at) < BOOT_SCREEN_MILLIS) { // boot screen
     // meshcore logo
     _display->setColor(UIColor::corp_blue);
     int logoWidth = 128;
@@ -716,6 +718,10 @@ void UITask::servicePairingState() {
 }
 
 void UITask::loop() {
+  // Observe startup expiry before button callbacks and optional rendering.
+  if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) >= 8000u) {
+    _startup_complete = true;
+  }
   const bool morse_timing = mesh::morseTimingActive(&radio_driver);
 #ifdef PIN_VIBRATION
   vibration.loop();
@@ -750,11 +756,11 @@ void UITask::loop() {
 
   if (!morse_timing && _display != NULL && _display->isOn()) {
     if (!isPairingScreenActive() && !_alert[0] && !(_origin[0] && _msg[0])
-        && (millis() - ui_started_at) >= BOOT_SCREEN_MILLIS) {
+        && (_startup_complete || static_cast<uint32_t>(millis() - ui_started_at) >= BOOT_SCREEN_MILLIS)) {
       serviceRadioProfileDisplayPage();
     }
     static bool _firstBoot = true;
-    if(_firstBoot && (millis() - ui_started_at) >= BOOT_SCREEN_MILLIS) {
+    if(_firstBoot && (_startup_complete || static_cast<uint32_t>(millis() - ui_started_at) >= BOOT_SCREEN_MILLIS)) {
       _need_refresh = true;
       _firstBoot = false;
     }
@@ -995,7 +1001,7 @@ void UITask::handleButtonLongPress() {
   _button_notification_cleared = false;
 #endif
   MESH_DEBUG_PRINTLN("UITask: long press triggered");
-  if (millis() - ui_started_at < 8000) {   // long press in first 8 seconds since startup -> CLI/rescue
+  if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) < 8000u) { // early-boot CLI/rescue only
     the_mesh.enterCLIRescue();
 #if defined(PIN_BUZZER) && MESH_GPS_VOICE
     // enterCLIRescue is supported independently of the framed USB interface.
diff --git a/examples/companion_radio/ui-orig/UITask.h b/examples/companion_radio/ui-orig/UITask.h
index 0c8fa855e..b74a92dda 100644
--- a/examples/companion_radio/ui-orig/UITask.h
+++ b/examples/companion_radio/ui-orig/UITask.h
@@ -56,6 +56,7 @@ class UITask : public AbstractUITask {
   unsigned long ui_started_at;
   uint32_t _radio_profile_page_started_at = 0;
   bool _dual_radio_enabled_seen = false;
+  bool _startup_complete = false;
   uint8_t _radio_profile_display_page = 0;
 
   // Button handlers
diff --git a/examples/companion_radio/ui-tiny/UITask.cpp b/examples/companion_radio/ui-tiny/UITask.cpp
index 5ef36b6fa..489c2652b 100644
--- a/examples/companion_radio/ui-tiny/UITask.cpp
+++ b/examples/companion_radio/ui-tiny/UITask.cpp
@@ -669,6 +669,7 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, CompanionNode
 #endif
 
   ui_started_at = millis();
+  _startup_complete = false;
   next_batt_chck = _next_refresh = ui_started_at;
   _alert[0] = 0;
   _alert_expiry = 0;
@@ -866,6 +867,10 @@ bool UITask::isButtonPressed() const {
 }
 
 void UITask::loop() {
+  // Observe startup expiry even while display/Morse/input defers rendering.
+  if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) >= 8000u) {
+    _startup_complete = true;
+  }
   const bool morse_timing = mesh::morseTimingActive(&radio_driver);
   servicePairingState();
 
@@ -1071,7 +1076,7 @@ char UITask::checkDisplayOn(char c) {
 }
 
 char UITask::handleLongPress(char c) {
-  if (millis() - ui_started_at < 8000) {   // long press in first 8 seconds since startup -> CLI/rescue
+  if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) < 8000u) { // early-boot CLI/rescue only
     the_mesh.enterCLIRescue();
     c = 0;   // consume event
   }
diff --git a/examples/companion_radio/ui-tiny/UITask.h b/examples/companion_radio/ui-tiny/UITask.h
index e92705413..a8dee7305 100644
--- a/examples/companion_radio/ui-tiny/UITask.h
+++ b/examples/companion_radio/ui-tiny/UITask.h
@@ -49,6 +49,7 @@ class UITask : public AbstractUITask {
   uint32_t next_batt_chck;
   uint32_t last_backlight_btn_check = 0;
   uint16_t _cached_batt_mv;
+  bool _startup_complete = false;
 #ifdef PIN_STATUS_LED
   int led_state = 0;
   uint32_t last_led_change = 0;
diff --git a/examples/simple_repeater/UITask.cpp b/examples/simple_repeater/UITask.cpp
index ccfbc3bdd..dc63ca00b 100644
--- a/examples/simple_repeater/UITask.cpp
+++ b/examples/simple_repeater/UITask.cpp
@@ -332,6 +332,7 @@ static const uint8_t meshcore_logo [] PROGMEM = {
 void UITask::begin(NodePrefs* node_prefs, const char* build_date, const char* firmware_version) {
   _prevBtnState = HIGH;
   _started_at = millis();
+  _startup_complete = false;
   _node_prefs = node_prefs;
   resetRadioProfileDisplayPage();
 #ifdef DISPLAY_ACTIVITY_DASHBOARD
@@ -418,7 +419,7 @@ void UITask::renderCurrScreen() {
 #ifdef DISPLAY_ACTIVITY_DASHBOARD
   _rows_valid = false;
 #endif
-  if ((uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) { // boot screen
+  if (!_startup_complete && (uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) { // boot screen
     // meshcore logo
     _display->setColor(UIColor::corp_blue);
     int logoWidth = 128;
@@ -635,7 +636,7 @@ uint32_t UITask::getFrameSignature() {
   uint32_t signature = DisplayFrameSignature::INITIAL;
   char tmp[80];
 
-  if ((uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) {
+  if (!_startup_complete && (uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) {
     signature = DisplayFrameSignature::append(signature, "boot");
     return DisplayFrameSignature::append(signature, _version_info);
   }
@@ -845,6 +846,10 @@ void UITask::toggleDisplay(const char* source) {
 #endif
 
 void UITask::loop() {
+  // Observe expiry outside display/Morse/input gates; startup is one-shot.
+  if (!_startup_complete && (uint32_t)(millis() - _started_at) >= BOOT_SCREEN_MILLIS) {
+    _startup_complete = true;
+  }
   const bool morse_timing = mesh::morseTimingActive(the_mesh.getProfileRadio());
   if (_display->servicePower(board.isExternalPowered() || board.isUsbHostConnected())) {
     if (_display->isOn()) resetRadioProfileDisplayPage();
diff --git a/examples/simple_repeater/UITask.h b/examples/simple_repeater/UITask.h
index 4c965f9b6..bd9fde913 100644
--- a/examples/simple_repeater/UITask.h
+++ b/examples/simple_repeater/UITask.h
@@ -27,6 +27,7 @@ class UITask {
   unsigned long _started_at = 0;
   uint8_t _radio_profile_display_page = 0;
   bool _dual_radio_enabled_seen = false;
+  bool _startup_complete = false;
 
   void resetRadioProfileDisplayPage();
   void advanceRadioProfileDisplayPage();
diff --git a/examples/simple_room_server/UITask.cpp b/examples/simple_room_server/UITask.cpp
index 69c34f5f8..c80a0827d 100644
--- a/examples/simple_room_server/UITask.cpp
+++ b/examples/simple_room_server/UITask.cpp
@@ -131,6 +131,7 @@ static const uint8_t meshcore_logo [] PROGMEM = {
 void UITask::begin(NodePrefs* node_prefs, const char* build_date, const char* firmware_version) {
   _prevBtnState = HIGH;
   _started_at = millis();
+  _startup_complete = false;
   _node_prefs = node_prefs;
   resetRadioProfileDisplayPage();
 #ifdef DISPLAY_ACTIVITY_DASHBOARD
@@ -188,7 +189,7 @@ void UITask::renderCurrScreen() {
 #ifdef DISPLAY_ACTIVITY_DASHBOARD
   _rows_valid = false;
 #endif
-  if ((uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) { // boot screen
+  if (!_startup_complete && (uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) { // boot screen
     // meshcore logo
     _display->setColor(UIColor::corp_blue);
     int logoWidth = 128;
@@ -341,7 +342,7 @@ uint32_t UITask::getFrameSignature() {
   uint32_t signature = DisplayFrameSignature::INITIAL;
   char tmp[80];
 
-  if ((uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) {
+  if (!_startup_complete && (uint32_t)(millis() - _started_at) < BOOT_SCREEN_MILLIS) {
     signature = DisplayFrameSignature::append(signature, "boot");
     return DisplayFrameSignature::append(signature, _version_info);
   }
@@ -496,6 +497,10 @@ void UITask::toggleDisplay(const char* source) {
 #endif
 
 void UITask::loop() {
+  // Observe expiry outside display/Morse/input gates; startup is one-shot.
+  if (!_startup_complete && (uint32_t)(millis() - _started_at) >= BOOT_SCREEN_MILLIS) {
+    _startup_complete = true;
+  }
   const bool morse_timing = mesh::morseTimingActive(the_mesh.getProfileRadio());
   if (_display->servicePower(board.isExternalPowered() || board.isUsbHostConnected())) {
     resetRadioProfileDisplayPage();
diff --git a/examples/simple_room_server/UITask.h b/examples/simple_room_server/UITask.h
index a407ec2bd..8af1c82a9 100644
--- a/examples/simple_room_server/UITask.h
+++ b/examples/simple_room_server/UITask.h
@@ -28,6 +28,7 @@ class UITask {
   unsigned long _started_at = 0;
   uint32_t _radio_profile_page_started_at = 0;
   bool _dual_radio_enabled_seen = false;
+  bool _startup_complete = false;
 #ifdef DISPLAY_TOUCH_TOGGLE
   unsigned long _powering_off_at = 0;
 #endif
diff --git a/examples/simple_sensor/UITask.cpp b/examples/simple_sensor/UITask.cpp
index 03fc01c67..3aaff8b85 100644
--- a/examples/simple_sensor/UITask.cpp
+++ b/examples/simple_sensor/UITask.cpp
@@ -105,6 +105,7 @@ void UITask::begin(NodePrefs* node_prefs, const char* build_date, const char* fi
   const uint32_t now = millis();
   _last_read = now - 200u;
   _last_refresh = now - 1000u;
+  _startup_complete = now >= BOOT_SCREEN_MILLIS;
 }
 
 void UITask::resetRadioProfileDisplayPage() {
@@ -128,7 +129,7 @@ bool UITask::showingSecondaryRadioProfilePage() {
 
 void UITask::renderCurrScreen() {
   char tmp[80];
-  if (millis() < BOOT_SCREEN_MILLIS) { // boot screen
+  if (!_startup_complete && millis() < BOOT_SCREEN_MILLIS) { // boot screen
     // meshcore logo
     _display->setColor(UIColor::corp_blue);
     int logoWidth = 128;
@@ -210,6 +211,10 @@ void UITask::renderCurrScreen() {
 }
 
 void UITask::loop() {
+  // This UI's splash is relative to boot, not to begin(). Retire it once.
+  if (!_startup_complete && millis() >= BOOT_SCREEN_MILLIS) {
+    _startup_complete = true;
+  }
   const bool morse_timing = mesh::morseTimingActive(activeSensorMesh().getProfileRadio());
   if (_display->servicePower(board.isExternalPowered() || board.isUsbHostConnected())) {
     resetRadioProfileDisplayPage();
diff --git a/examples/simple_sensor/UITask.h b/examples/simple_sensor/UITask.h
index b10f3a799..f7b03e7af 100644
--- a/examples/simple_sensor/UITask.h
+++ b/examples/simple_sensor/UITask.h
@@ -12,6 +12,7 @@ class UITask {
   char _version_info[32];
   uint32_t _radio_profile_page_started_at = 0;
   bool _dual_radio_enabled_seen = false;
+  bool _startup_complete = false;
 
   void resetRadioProfileDisplayPage();
   bool showingSecondaryRadioProfilePage();
diff --git a/test/fixtures/companion_ui_deadlines.cpp b/test/fixtures/companion_ui_deadlines.cpp
index 245ae5759..74738666a 100644
--- a/test/fixtures/companion_ui_deadlines.cpp
+++ b/test/fixtures/companion_ui_deadlines.cpp
@@ -5,12 +5,15 @@
 #include <cstdint>
 #include <cstdio>
 #include <cstring>
+#include <initializer_list>
 
 static uint32_t now_ms = 0;
 static uint32_t millis() { return now_ms; }
 static void delay(uint32_t duration) { now_ms += duration; }
 static constexpr uint32_t BOOT_SCREEN_MILLIS = 3000;
+#define MESH_DEBUG_PRINTLN(...) do {} while (0)
 struct Radio { bool timing = false; } radio_driver;
+struct TestMesh { unsigned rescues = 0; void enterCLIRescue() { ++rescues; } } the_mesh;
 namespace mesh {
 static bool morseTimingActive(const Radio* radio) { return radio && radio->timing; }
 namespace ui { enum class DisplayWake { Button }; }
@@ -52,6 +55,8 @@ struct UITask {
   HomeScreen screen;
   UIScreen* curr = &screen;
   UIScreen* home = &screen;
+  UIScreen preview;
+  UIScreen* msg_preview = &preview;
   StatusBar _statusBar;
   struct Prefs { const char* node_name = "test"; } prefs;
   Prefs* _node_prefs = &prefs;
@@ -59,10 +64,11 @@ struct UITask {
   uint32_t _next_refresh = 0, _alert_expiry = 0, ui_started_at = 0, next_batt_chck = 0;
   uint32_t _pairing_screen_until = 0;
   bool _pairing_from_button = false;
+  bool _startup_complete = false;
   uint16_t _cached_batt_mv = 4000, voltage = 4000;
   bool gesture_pending = false;
   bool _need_refresh = true;
-  unsigned battery_reads = 0, shutdowns = 0;
+  unsigned battery_reads = 0, shutdowns = 0, profile_services = 0;
   char _alert[80] = {}, _origin[80] = {}, _msg[80] = {};
   void servicePairingState() {}
   void serviceWiFiToggleButton() {}
@@ -73,13 +79,15 @@ struct UITask {
   bool isBluetoothEnabled() const { return false; }
   void userLedHandler() {}
   void renderPairingBanner() {}
-  void serviceRadioProfileDisplayPage() {}
+  void serviceRadioProfileDisplayPage() { ++profile_services; }
   void renderCurrScreen() { ++screen.renders; _need_refresh = false; }
   uint16_t getBattMilliVolts() { ++battery_reads; return voltage; }
   void shutdown() { ++shutdowns; }
   void showAlert(const char* text, int duration_millis);
   void setCurrScreen(UIScreen* screen);
   void loop();
+  void handleButtonLongPress();
+  char handleLongPress(char);
 };
 @LOOP@
 @ALERT@
@@ -100,6 +108,76 @@ int main(int argc, char** argv) {
   assert(argc == 2);
   const char* scenario = argv[1];
   UITask ui;
+  if (!std::strcmp(scenario, "startup-first-draw")) {
+#if UI_ORIG
+    ui.ui_started_at = now_ms = 1000;
+    ui._need_refresh = false;
+    ui.display.on = false;
+    ui.loop();
+    now_ms = 9000; ui.loop();
+    for (uint64_t day = 1; day <= 49; ++day) {
+      now_ms = uint32_t(1000u + day * 86400000ULL);
+      ui.loop();
+    }
+    now_ms = 2000; ui.loop(); // Full-wrap alias, startup already observed closed.
+    ui.display.on = true; ui.loop();
+    assert(ui.display.frames == 1 && "deferred first paint must remain post-startup after full wrap");
+#endif
+    std::puts("PASS: startup-first-draw");
+    return 0;
+  }
+  if (!std::strcmp(scenario, "startup-one-shot")) {
+    for (uint32_t started : {0u, 1000u, UINT32_MAX - 4000u}) {
+      for (unsigned gate = 0; gate < 4; ++gate) {
+        UITask window;
+        window.ui_started_at = started;
+        window._next_refresh = now_ms = started;
+        window.display.on = (gate & 1) == 0;
+        radio_driver.timing = (gate & 2) != 0;
+        window.loop();
+        now_ms = started + 7999u; window.loop();
+        const auto before = the_mesh.rescues;
+#if UI_ORIG
+        window.handleButtonLongPress();
+#else
+        assert(window.handleLongPress('x') == 0);
+#endif
+        assert(the_mesh.rescues == before + 1 && !window._startup_complete);
+        now_ms = started + 8000u; window.loop();
+#if UI_ORIG
+        window.handleButtonLongPress();
+        assert(window.shutdowns == 1);
+#else
+        assert(window.handleLongPress('x') == 'x');
+#endif
+        assert(the_mesh.rescues == before + 1); // Exact 8-second cutoff.
+        for (uint64_t day = 1; day <= 49; ++day) {
+          now_ms = uint32_t(started + day * 86400000ULL);
+          window.loop();
+        }
+        // Live observation of expiry precedes the complete-counter alias.
+        now_ms = started + 1000u; window.loop();
+        window.display.on = true; radio_driver.timing = false;
+        const auto profiles = window.profile_services;
+        window.loop();
+#if UI_ORIG
+        window.handleButtonLongPress();
+#else
+        (void)profiles;
+        const char returned = window.handleLongPress('x');
+#endif
+        assert(the_mesh.rescues == before + 1 && window._startup_complete
+            && "expired startup rescue must never reopen after full wrap");
+#if UI_ORIG
+        assert(window.shutdowns == 2 && window.profile_services == profiles + 1);
+#else
+        assert(returned == 'x');
+#endif
+      }
+    }
+    std::puts("PASS: startup-one-shot");
+    return 0;
+  }
   if (!std::strcmp(scenario, "orig-long-clean-idle")) {
 #if UI_ORIG
     now_ms = 0x90001000u;
diff --git a/test/fixtures/infrastructure_ui_version.cpp b/test/fixtures/infrastructure_ui_version.cpp
index c036168ba..6fda8f45b 100644
--- a/test/fixtures/infrastructure_ui_version.cpp
+++ b/test/fixtures/infrastructure_ui_version.cpp
@@ -5,6 +5,7 @@
 #include <string>
 
 static uint32_t now_ms;
+static constexpr uint32_t BOOT_SCREEN_MILLIS = 4000;
 static uint32_t millis() { return now_ms; }
 static constexpr int HIGH = 1;
 static bool deny_copy;
diff --git a/test/fixtures/sensor_ui_polling.cpp b/test/fixtures/sensor_ui_polling.cpp
index 6679c624d..9584176a3 100644
--- a/test/fixtures/sensor_ui_polling.cpp
+++ b/test/fixtures/sensor_ui_polling.cpp
@@ -8,6 +8,7 @@ static uint32_t now_ms = 0, read_delay = 0, render_delay = 0, end_delay = 0;
 static unsigned reads = 0, renders = 0;
 static constexpr int HIGH = 1, LOW = 0, USER_BTN_PRESSED = LOW;
 static constexpr int BUTTON_EVENT_NONE = 0;
+static constexpr uint32_t BOOT_SCREEN_MILLIS = 4000;
 static int button_level = HIGH;
 static uint32_t millis() { return now_ms; }
 [[maybe_unused]] static int digitalRead(int pin) {
diff --git a/test/fixtures/ui_startup_windows.cpp b/test/fixtures/ui_startup_windows.cpp
new file mode 100644
index 000000000..e1a0e2823
--- /dev/null
+++ b/test/fixtures/ui_startup_windows.cpp
@@ -0,0 +1,201 @@
+// Actual Sensor UI methods and header; infrastructure init/prefix/metadata only.
+// Hardware, optional status-page and radio dependencies are explicit adapters.
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+
+static uint32_t now_ms = 0;
+static uint32_t millis() { return now_ms; }
+static constexpr int HIGH = 1;
+enum class UIColor { corp_blue, primary_txt, secondary_txt, warning_txt };
+namespace mesh {
+struct Params { float freq = 915, bw = 125; uint8_t sf = 7, cr = 5; };
+struct RadioProfiles {
+  bool enabled() const { return false; }
+  bool secondary_temporary = false, primary_temporary = false;
+  const Params& params(int) const { static Params value; return value; }
+};
+struct MainBoard {
+  bool isExternalPowered() const { return true; }
+  bool isUsbHostConnected() const { return true; }
+};
+namespace ui {
+enum class DisplayWake { Button };
+struct RadioProfileSystemStatus {};
+[[maybe_unused]] static bool showSecondaryRadioProfilePage(bool, uint8_t, uint32_t) {
+  return false;
+}
+[[maybe_unused]] static bool showRadioProfileSystemStatusPage(bool, uint8_t, uint32_t,
+                                                           uint8_t*) { return false; }
+[[maybe_unused]] static const char* radioProfileDisplayTag(int, bool) { return ""; }
+}
+}
+struct DisplayDriver {
+  bool on = true, changed = false;
+  unsigned frames = 0, logos = 0, homes = 0;
+  bool servicePower(bool) { bool result = changed; changed = false; return result; }
+  bool isOn() const { return on; }
+  void wake(mesh::ui::DisplayWake) { on = true; }
+  void startFrame() { ++frames; }
+  void endFrame() {}
+  void setColor(UIColor) {}
+  void setTextSize(float) {}
+  void setCursor(int, int) {}
+  int width() const { return 128; }
+  unsigned getTextWidth(const char* text) const { return std::strlen(text) * 6; }
+  void drawXbm(int, int, const uint8_t*, int, int) { ++logos; }
+  void print(const char* text) { if (!std::strcmp(text, "normal-node")) ++homes; }
+};
+namespace mesh { namespace ui {
+[[maybe_unused]] static void drawRadioProfileSystemStatusPage(
+    DisplayDriver&, const RadioProfileSystemStatus&, uint8_t) {}
+}}
+static mesh::MainBoard board;
+struct Radio { bool timing = false; } radio;
+namespace mesh {
+[[maybe_unused]] static bool morseTimingActive(const Radio* value) { return value->timing; }
+}
+struct SensorMesh {
+  Radio* getProfileRadio() { return &radio; }
+  bool isDualRadioActive() const { return false; }
+} sensor_mesh;
+[[maybe_unused]] static SensorMesh& activeSensorMesh() { return sensor_mesh; }
+static SensorMesh& the_mesh = sensor_mesh;
+struct NodePrefs {
+  char node_name[32] = "normal-node";
+  float freq = 915, bw = 125;
+  uint8_t sf = 7, cr = 5;
+};
+[[maybe_unused]] static const mesh::RadioProfiles* configuredRadioProfiles() { return nullptr; }
+[[maybe_unused]] static mesh::ui::RadioProfileSystemStatus radioProfileSystemStatus(
+    const NodePrefs&) { return {}; }
+[[maybe_unused]] static uint8_t radioProfileStatusPageCount(DisplayDriver&, bool) { return 0; }
+[[maybe_unused]] static const uint8_t meshcore_logo[] = {0};
+#define BOOT_SCREEN_MILLIS 4000
+#include "UITask.h"
+
+@METHODS@
+
+static const char* scenario;
+static unsigned checks = 0;
+#define CHECK(expression) do { ++checks; if (!(expression)) { \
+  std::fprintf(stderr, "FAIL %s: %s (line %d)\n", scenario, #expression, __LINE__); \
+  return 1; } } while (0)
+
+int main(int argc, char** argv) {
+  if (argc != 2) return 2;
+  scenario = argv[1];
+  DisplayDriver display;
+  NodePrefs prefs;
+#if TEST_REPEATER
+  UITask ui(board, display);
+#else
+  UITask ui(display);
+#endif
+#if TEST_SENSOR
+  const bool late = !std::strcmp(scenario, "late-begin");
+  const bool upper = !std::strcmp(scenario, "upper-begin");
+  const bool maximum = !std::strcmp(scenario, "max-begin");
+  const bool off_first = !std::strcmp(scenario, "off-first");
+  const bool morse_first = !std::strcmp(scenario, "morse-first");
+  now_ms = late ? 4000u : upper ? 0x80001000u : maximum ? UINT32_MAX : 0u;
+  display.on = !off_first;
+  radio.timing = morse_first;
+  ui.begin(&prefs, "16 Oct 2026", "v1.2.3-test");
+  ui.loop();
+  CHECK(display.logos == unsigned(!late && !upper && !maximum && !off_first && !morse_first));
+  CHECK(display.homes == unsigned(late || upper || maximum));
+  if (!std::strcmp(scenario, "boundary")) {
+    now_ms = 3999;
+    display.changed = true;
+    ui.loop();
+    CHECK(display.logos == 2 && display.homes == 0);
+    now_ms = 4000;
+    display.changed = true;
+    ui.loop();
+    CHECK(display.logos == 2 && display.homes == 1);
+  } else if (late || upper || maximum) {
+    // Re-entering the low boot clock range must not undo begin's late cutoff.
+    now_ms = 0;
+    display.changed = true;
+    ui.loop();
+    CHECK(display.logos == 0 && display.homes == 2);
+  } else if (!std::strcmp(scenario, "live-wrap")) {
+    now_ms = 5000;
+    ui.loop();
+    CHECK(display.logos == 1 && display.homes == 1);
+    for (uint64_t day = 1; day <= 49; ++day) {
+      now_ms = static_cast<uint32_t>(day * 86400000ULL);
+      ui.loop();
+      CHECK(display.logos == 1);
+    }
+    const unsigned homes = display.homes;
+    now_ms = 0; // absolute 2^32, reached after the live checkpoints above
+    ui.loop();
+    CHECK(display.logos == 1 && display.homes == homes + 1);
+  } else if (!std::strcmp(scenario, "off-retirement")
+      || !std::strcmp(scenario, "morse-retirement") || off_first || morse_first) {
+    const bool off = off_first || !std::strcmp(scenario, "off-retirement");
+    display.on = !off;
+    radio.timing = !off;
+    const unsigned frames = display.frames, logos = display.logos;
+    now_ms = 4000;
+    ui.loop();
+    CHECK(display.frames == frames);
+    now_ms = 0; // full-wrap alias, after observed expiry with no rendered frame
+    display.on = true;
+    display.changed = true;
+    radio.timing = false;
+    ui.loop();
+    CHECK(display.logos == logos && display.homes == 1);
+  } else if (!std::strcmp(scenario, "wake")) {
+    now_ms = 4000;
+    ui.loop();
+    CHECK(display.logos == 1 && display.homes == 1);
+    display.on = false;
+    now_ms = 12000;
+    ui.loop();
+    now_ms = 0;
+    display.wake(mesh::ui::DisplayWake::Button);
+    display.changed = true;
+    ui.loop();
+    CHECK(display.logos == 1 && display.homes == 2);
+  } else if (!std::strcmp(scenario, "rebegin")) {
+    now_ms = 4000;
+    ui.loop();
+    CHECK(display.logos == 1 && display.homes == 1);
+    now_ms = 100;
+    ui.begin(&prefs, "16 Oct 2026", "v1.2.3-test");
+    ui.loop();
+    CHECK(display.logos == 2 && display.homes == 1);
+    now_ms = 4100;
+    ui.loop();
+    CHECK(display.logos == 2 && display.homes == 2);
+    now_ms = 5000;
+    ui.begin(&prefs, "16 Oct 2026", "v1.2.3-test");
+    ui.loop();
+    CHECK(display.logos == 2 && display.homes == 3);
+  } else return 3;
+#else
+  const bool wrapping = !std::strcmp(scenario, "infra-wrap-start");
+  const uint32_t start = wrapping ? UINT32_MAX - 1000u : 1000u;
+  now_ms = start;
+  ui.begin(&prefs, "16 Oct 2026", "v1.2.3-test");
+  CHECK(ui.testRenderBoot() && ui.testSignatureBoot());
+  now_ms = start + 3999u;
+  ui.loop();
+  CHECK(ui.testRenderBoot() && ui.testSignatureBoot());
+  now_ms = start + 4000u;
+  ui.loop();
+  CHECK(!ui.testRenderBoot() && !ui.testSignatureBoot());
+  now_ms = start; // full-wrap alias, same retained boot timestamp
+  ui.loop();
+  CHECK(!ui.testRenderBoot() && !ui.testSignatureBoot());
+  if (!std::strcmp(scenario, "infra-rebegin")) {
+    ui.begin(&prefs, "16 Oct 2026", "v1.2.3-test");
+    CHECK(ui.testRenderBoot() && ui.testSignatureBoot());
+  } else if (std::strcmp(scenario, "infra-boundary") && !wrapping) return 3;
+#endif
+  std::printf("PASS %s (%u checks)\n", scenario, checks);
+}
diff --git a/test/test_button_voice_actions.py b/test/test_button_voice_actions.py
index 081cd4c5d..e64b55157 100644
--- a/test/test_button_voice_actions.py
+++ b/test/test_button_voice_actions.py
@@ -293,6 +293,7 @@ struct UITask {
  char _alert[80]={},_origin[80]={},_msg[80]={};
  bool _need_refresh=false,_displayWasOn=false,_button_notification_cleared=false;
  bool _shutdown_pending=false,_shutdown_restart=false;
+ bool _startup_complete=false;
  uint32_t _shutdown_started_at=0,ui_started_at=0;
  uint8_t _radio_profile_display_page=0,_notification_outputs=mesh::notify::Sound;
  bool guard_ok=true,guard_reject_drain=false;unsigned guards=0,preview_clears=0;
diff --git a/test/test_companion_ui_deadlines.py b/test/test_companion_ui_deadlines.py
index b383a0c73..5d6573a5b 100644
--- a/test/test_companion_ui_deadlines.py
+++ b/test/test_companion_ui_deadlines.py
@@ -30,27 +30,58 @@ class CompanionUiDeadlineTests(unittest.TestCase):
         cls.addClassCleanup(cls.directory.cleanup)
         work = Path(cls.directory.name)
         cls.binaries = {}
+        cls.startup_mutants = {}
+        cls.first_paint_mutant = None
         for variant in BUILD_VARIANTS:
             source_variant = 'ui-tiny' if variant == 'ui-tiny-cache' else variant
             source = (ROOT / f'examples/companion_radio/{source_variant}/UITask.cpp').read_text(encoding='ascii')
             generated = FIXTURE.read_text(encoding='ascii').replace('@LOOP@', extract_braced(source, 'void UITask::loop()'))
+            handler = ('void UITask::handleButtonLongPress()' if source_variant == 'ui-orig'
+                       else 'char UITask::handleLongPress(char c)')
+            generated += '\n' + extract_braced(source, handler) + '\n'
             generated = generated.replace('@ALERT@', '' if variant == 'ui-orig' else
                                           extract_braced(source, 'void UITask::showAlert('))
             generated = generated.replace('@SCREEN@', '' if variant == 'ui-orig' else
                                           extract_braced(source, 'void UITask::setCurrScreen('))
             cpp, binary = work / (variant + '.cpp'), work / variant
             cpp.write_text(generated, encoding='ascii')
-            built = subprocess.run([
+            command = [
                 compiler, '-std=c++17', '-Wall', '-Wextra', '-Werror', '-Wno-unused-function',
                 '-fsanitize=address,undefined', '-fno-sanitize-recover=all', '-fno-pie', '-no-pie',
                 '-DUI_ORIG=' + str(int(variant == 'ui-orig')), '-DUI_HAS_JOYSTICK=0',
                 '-DUI_TINY_CACHE=' + str(int(variant == 'ui-tiny-cache')),
                 '-DCOMPANION_FEATURE_READER=0', '-DAUTO_OFF_MILLIS=0',
                 *([] if variant in ('ui-orig', 'ui-tiny-cache') else ['-DAUTO_SHUTDOWN_MILLIVOLTS=3400']),
-                str(cpp), '-o', str(binary)], capture_output=True, text=True, timeout=60)
+                str(cpp), '-o', str(binary)]
+            built = subprocess.run(command, capture_output=True, text=True, timeout=60)
             if built.returncode:
                 raise AssertionError(built.stdout + built.stderr)
             cls.binaries[variant] = binary
+            latch = extract_braced(source,
+                'if (!_startup_complete && static_cast<uint32_t>(millis() - ui_started_at) >= 8000u)')
+            if generated.count(latch) != 1:
+                raise AssertionError('startup retirement must appear once in the complete foreground loop')
+            mutant_cpp, mutant_binary = work / (variant + '-startup.cpp'), work / (variant + '-startup')
+            mutant_cpp.write_text(generated.replace(latch, '', 1), encoding='ascii')
+            mutant_command = [str(mutant_cpp) if arg == str(cpp)
+                              else str(mutant_binary) if arg == str(binary) else arg for arg in command]
+            built = subprocess.run(mutant_command, capture_output=True, text=True, timeout=60)
+            if built.returncode:
+                raise AssertionError(built.stdout + built.stderr)
+            cls.startup_mutants[variant] = mutant_binary
+            if variant == 'ui-orig':
+                first_paint = extract_braced(source, 'if(_firstBoot &&')
+                if first_paint.count('_startup_complete || ') != 1:
+                    raise AssertionError('first paint must recognize completed startup')
+                mutant_cpp, mutant_binary = work / 'orig-first-paint.cpp', work / 'orig-first-paint'
+                mutant_cpp.write_text(generated.replace(first_paint,
+                    first_paint.replace('_startup_complete || ', '', 1), 1), encoding='ascii')
+                mutant_command = [str(mutant_cpp) if arg == str(cpp)
+                                  else str(mutant_binary) if arg == str(binary) else arg for arg in command]
+                built = subprocess.run(mutant_command, capture_output=True, text=True, timeout=60)
+                if built.returncode:
+                    raise AssertionError(built.stdout + built.stderr)
+                cls.first_paint_mutant = mutant_binary
 
     def check_scenario(self, scenario, variants=VARIANTS):
         for variant in variants:
@@ -64,6 +95,24 @@ class CompanionUiDeadlineTests(unittest.TestCase):
     def test_healthy_refresh_schedule(self):
         self.check_scenario('healthy')
 
+    def test_startup_rescue_retires_outside_gates_and_stays_closed_after_full_wrap(self):
+        self.check_scenario('startup-one-shot', BUILD_VARIANTS)
+
+    def test_missing_foreground_startup_retirement_is_rejected(self):
+        for variant, binary in self.startup_mutants.items():
+            with self.subTest(variant=variant):
+                checked = subprocess.run([str(binary), 'startup-one-shot'],
+                                         capture_output=True, text=True, timeout=10)
+                self.assertNotEqual(checked.returncode, 0)
+                self.assertIn('expired startup rescue must never reopen after full wrap', checked.stderr)
+
+    def test_orig_first_paint_can_be_deferred_past_startup_and_wrap(self):
+        self.check_scenario('startup-first-draw', ('ui-orig',))
+        checked = subprocess.run([str(self.first_paint_mutant), 'startup-first-draw'],
+                                 capture_output=True, text=True, timeout=10)
+        self.assertNotEqual(checked.returncode, 0)
+        self.assertIn('deferred first paint must remain post-startup after full wrap', checked.stderr)
+
     def test_upper_half_refresh_schedule(self):
         self.check_scenario('upper-half')
 
@@ -140,6 +189,8 @@ class CompanionUiDeadlineWiringContract(unittest.TestCase):
                 # every actual begin/re-begin must re-arm from its fresh clock.
                 self.assertRegex(constructor, r'\b_next_refresh\s*=\s*0\s*;')
                 self.assertIn('ui_started_at = millis();', begin)
+                self.assertIn('_startup_complete = false;', begin)
+                self.assertIn('bool _startup_complete = false;', header)
                 self.assertLess(begin.index('ui_started_at = millis();'),
                                 begin.index('_next_refresh = ui_started_at;'))
                 without_constructor = header.replace(constructor, '', 1)
diff --git a/test/test_esp32_usb_sleep.py b/test/test_esp32_usb_sleep.py
index 9215e8ee9..16258e86e 100644
--- a/test/test_esp32_usb_sleep.py
+++ b/test/test_esp32_usb_sleep.py
@@ -388,8 +388,11 @@ struct TestDisplay {
   bool isOn() const { return policy.on(); }
   void wake(mesh::ui::DisplayWake reason) { policy.wake(reason, millis()); }
 } display;
+static constexpr uint32_t BOOT_SCREEN_MILLIS = 4000;
 struct UITask {
   TestDisplay* _display = &display;
+  bool _startup_complete = false;
+  uint32_t _started_at = 0;
   uint32_t _next_refresh = 0, _powering_off_at = 0, _next_read = 0;
   uint32_t _last_refresh = 0, _last_read = 0; // Sensor uses elapsed-time anchors.
   int _prevBtnState = HIGH;
diff --git a/test/test_heltec_v4_wifi_setup_page.py b/test/test_heltec_v4_wifi_setup_page.py
index 059a06211..e0c745d48 100644
--- a/test/test_heltec_v4_wifi_setup_page.py
+++ b/test/test_heltec_v4_wifi_setup_page.py
@@ -244,6 +244,7 @@ int main() {
         source = r'''
 #include <cassert>
 #define UI_WIFI_SETUP_HOME_PAGE 1
+#include <cstdint>
 unsigned long now = 4000;
 unsigned long millis() { return now; }
 struct Screen {};
@@ -260,6 +261,7 @@ struct UITask {
   Screen* home;
   Screen* msg_preview;
   unsigned long ui_started_at = 0;
+  bool _startup_complete = false;
   char handleLongPress(char c);
 };
 ''' + ui[start:end] + r'''
diff --git a/test/test_legacy_ui_version_bounds.py b/test/test_legacy_ui_version_bounds.py
index 2e92cea15..dabed78ef 100644
--- a/test/test_legacy_ui_version_bounds.py
+++ b/test/test_legacy_ui_version_bounds.py
@@ -54,6 +54,7 @@ struct UITask {
   CompanionNodePrefs* _node_prefs = nullptr;
   unsigned clears = 0, resets = 0;
   unsigned long ui_started_at = 0, _next_refresh = 0;
+  bool _startup_complete = false;
   explicit UITask(char (&label)[@CAPACITY@]) : _version_info(label) {}
   void clearMsgPreview() { ++clears; }
   void resetRadioProfileDisplayPage() { ++resets; }
diff --git a/test/test_morse_loop_policy.py b/test/test_morse_loop_policy.py
index 6503c1e27..66cf2ab68 100644
--- a/test/test_morse_loop_policy.py
+++ b/test/test_morse_loop_policy.py
@@ -70,6 +70,7 @@ struct UI {
   uint32_t _last_refresh=0;
   uint16_t _cached_batt_mv=4000,voltage=3350;
   bool _need_refresh=true;
+  bool _startup_complete=false;
   char _alert[4]={},_origin[4]={},_msg[4]={};
   bool isButtonGesturePending() { return false; }
   bool isPairingScreenActive() { return false; }
diff --git a/test/test_ui_startup_windows.py b/test/test_ui_startup_windows.py
new file mode 100644
index 000000000..323baf2ff
--- /dev/null
+++ b/test/test_ui_startup_windows.py
@@ -0,0 +1,161 @@
+"""Check one-shot infrastructure startup windows with a real uint32 clock.
+
+Sensor coverage compiles its actual header, complete begin, page methods,
+renderer and foreground loop. Repeater/Room coverage compiles their headers,
+begin/reset methods, exact renderer/signature boot expressions and actual loop
+prefix only. Board, radio, display and optional page helpers are host adapters;
+this does not qualify complete infrastructure rendering or physical hardware.
+"""
+from pathlib import Path
+import os
+import re
+import shutil
+import subprocess
+import sys
+import tempfile
+import unittest
+
+from test_replay_reset_integration import extract_braced
+
+ROOT = Path(__file__).resolve().parents[1]
+FIXTURE = ROOT / 'test/fixtures/ui_startup_windows.cpp'
+ROLES = ('simple_sensor', 'simple_repeater', 'simple_room_server')
+
+
+def startup_retirement(loop):
+    """Extract the real first retirement branch, never a handwritten predicate."""
+    return extract_braced(loop, 'if (!_startup_complete &&')
+
+
+def boot_expression(method):
+    matched = re.search(r'\bif\s*\(([^\n]*_startup_complete[^\n]*)\)\s*\{', method)
+    if not matched:
+        raise AssertionError('expected a guarded single-line startup expression')
+    return matched.group(1)
+
+
+class UiStartupWindowsTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        compiler = os.environ.get('CXX') or shutil.which('g++') or shutil.which('clang++')
+        if not compiler:
+            raise unittest.SkipTest('a host C++17 compiler is required')
+        cls.temp = tempfile.TemporaryDirectory(prefix='ui-startup-windows-')
+        cls.addClassCleanup(cls.temp.cleanup)
+        work = Path(cls.temp.name)
+        (work / 'helpers/ui').mkdir(parents=True)
+        for stub in ('helpers/ui/DisplayDriver.h', 'helpers/CommonCLI.h'):
+            (work / stub).write_text('#pragma once\n', encoding='ascii')
+        sanitize = [] if not sys.platform.startswith('linux') else [
+            '-fsanitize=address,undefined', '-fno-sanitize-recover=all',
+            '-fno-omit-frame-pointer', '-fno-pie', '-no-pie']
+        cls.binaries = {}
+        fixture = FIXTURE.read_text(encoding='ascii')
+        for role in ROLES:
+            folder = ROOT / 'examples' / role
+            source = (folder / 'UITask.cpp').read_text(encoding='ascii')
+            header = (folder / 'UITask.h').read_text(encoding='ascii')
+            if header.count('class UITask {') != 1:
+                raise AssertionError('expected one real UI class')
+            header = header.replace('class UITask {', 'struct UITask {')
+            # Only expose observations; no extra state or changed declarations.
+            header = header.replace('public:',
+                                    'bool testRenderBoot();\n  bool testSignatureBoot();\npublic:', 1)
+            directory = work / role
+            directory.mkdir()
+            (directory / 'UITask.h').write_text(header, encoding='ascii')
+            begin = extract_braced(source, 'void UITask::begin(')
+            reset = extract_braced(source, 'void UITask::resetRadioProfileDisplayPage(')
+            loop = extract_braced(source, 'void UITask::loop()')
+            if role == 'simple_sensor':
+                methods = '\n'.join((begin, reset,
+                    extract_braced(source, 'bool UITask::showingSecondaryRadioProfilePage('),
+                    extract_braced(source, 'void UITask::renderCurrScreen()'), loop))
+            else:
+                prefix = loop[:loop.index('  const bool morse_timing')]
+                render = extract_braced(source, 'void UITask::renderCurrScreen()')
+                signature = extract_braced(source, 'uint32_t UITask::getFrameSignature()')
+                methods = '\n'.join((begin, reset, prefix + '}\n',
+                    'void UITask::applyDisplayFlip() {}',
+                    'bool UITask::testRenderBoot() { return ' + boot_expression(render) + '; }',
+                    'bool UITask::testSignatureBoot() { return ' + boot_expression(signature) + '; }'))
+            variants = [('production', methods)]
+            if role == 'simple_sensor':
+                retirement = startup_retirement(loop)
+                if methods.count(retirement) != 1:
+                    raise AssertionError('expected exactly one actual retirement branch')
+                variants.append(('no-retirement', methods.replace(retirement, '', 1)))
+            for kind, generated_methods in variants:
+                cpp = directory / (kind + '.cpp')
+                cpp.write_text(fixture.replace('@METHODS@', generated_methods), encoding='ascii')
+                binary = directory / (kind + ('.exe' if os.name == 'nt' else ''))
+                built = subprocess.run([
+                    compiler, '-std=c++17', '-O1', '-g', '-Wall', '-Wextra', '-Werror',
+                    *sanitize, '-DTEST_SENSOR=' + str(int(role == 'simple_sensor')),
+                    '-DTEST_REPEATER=' + str(int(role == 'simple_repeater')),
+                    '-I' + str(work), str(cpp), '-o', str(binary)],
+                    capture_output=True, text=True, timeout=60)
+                if built.returncode:
+                    raise AssertionError(built.stdout + built.stderr)
+                cls.binaries[role, kind] = binary
+
+    def check_case(self, case, roles=('simple_sensor',), kind='production', fails=False):
+        for role in roles:
+            with self.subTest(role=role, case=case, kind=kind):
+                checked = subprocess.run([str(self.binaries[role, kind]), case],
+                                         capture_output=True, text=True, timeout=10)
+                if fails:
+                    self.assertNotEqual(checked.returncode, 0, checked.stdout)
+                    self.assertIn('FAIL ' + case, checked.stderr)
+                    self.assertNotIn('runtime error:', checked.stderr)
+                    self.assertNotIn('AddressSanitizer:', checked.stderr)
+                else:
+                    self.assertEqual(checked.returncode, 0, checked.stdout + checked.stderr)
+                    self.assertIn('PASS ' + case, checked.stdout)
+
+    def test_sensor_exact_boot_boundary_and_absolute_late_begin(self):
+        for case in ('boundary', 'late-begin', 'upper-begin', 'max-begin'):
+            self.check_case(case)
+
+    def test_sensor_live_loops_do_not_replay_after_full_clock_wrap(self):
+        self.check_case('live-wrap')
+
+    def test_sensor_retires_without_display_or_morse_rendering(self):
+        for case in ('off-retirement', 'morse-retirement',
+                     'off-first', 'morse-first'):
+            self.check_case(case)
+
+    def test_sensor_normal_wake_and_rebegin_preserve_startup_policy(self):
+        for case in ('wake', 'rebegin'):
+            self.check_case(case)
+
+    def test_removing_actual_sensor_retirement_reproduces_semantic_failure(self):
+        for case in ('live-wrap', 'off-retirement', 'morse-retirement',
+                     'off-first', 'morse-first'):
+            self.check_case(case, kind='no-retirement', fails=True)
+
+    def test_infrastructure_actual_init_prefix_and_render_metadata(self):
+        for case in ('infra-boundary', 'infra-wrap-start', 'infra-rebegin'):
+            self.check_case(case, ('simple_repeater', 'simple_room_server'))
+
+    def test_retirement_is_before_hardware_and_rendering_gates(self):
+        for role in ROLES:
+            with self.subTest(role=role):
+                folder = ROOT / 'examples' / role
+                source = (folder / 'UITask.cpp').read_text(encoding='ascii')
+                header = (folder / 'UITask.h').read_text(encoding='ascii')
+                self.assertRegex(header, r'bool _startup_complete\s*=\s*false;')
+                loop = extract_braced(source, 'void UITask::loop()')
+                retired = startup_retirement(loop)
+                self.assertIn('_startup_complete = true;', retired)
+                self.assertLess(loop.index(retired), loop.index('const bool morse_timing'))
+                self.assertLess(loop.index(retired), loop.index('servicePower('))
+                main = (folder / 'main.cpp').read_text(encoding='ascii')
+                self.assertIn('ui_task.begin(', extract_braced(main, 'void setup()'))
+                # Room's alternative preprocessor branches have unmatched
+                # braces before preprocessing; do not parse them as one block.
+                self.assertIn('ui_task.loop();', main[main.index('\nvoid loop()'):])
+
+
+if __name__ == '__main__':
+    unittest.main()