Fix SENSOR power saving deep sleep truncating TX and skipping sleep on failed reads (#10939)

* Fix SENSOR power saving deep sleep behavior

Deep sleep could be entered while a telemetry packet was still queued
or on air, truncating the transmission. canSleep() gained a deepSleep
parameter and now vetoes in that case; light sleep is unchanged.
Telemetry modules defer a pending deep sleep (bounded to 30s) until the
radio is idle and no longer let the sensor polling interval override
the 5s pre-sleep grace period. A failed sensor read still arms deep
sleep instead of leaving the node awake for a full telemetry interval.

Fixes #10890
Fixes #10932

* Deduplicate telemetry deep sleep deferral logic

Move the radio-busy deferral and its counter into BaseTelemetryModule
and add an isPowerSavingSensor() helper. Removes the telemetry-specific
counter from OSThread. The sleep arming block stays per module because
it needs protected OSThread members not visible to the base class.

src/modules/Telemetry/EnvironmentTelemetry.cpp

@@ -253,6 +253,8 @@ void EnvironmentTelemetryModule::i2cScanFinished(ScanI2C *i2cScanner)
 int32_t EnvironmentTelemetryModule::runOnce()
 {
     if (sleepOnNextExecution == true) {
+        if (shouldDeferDeepSleep())
+            return PREFLIGHT_SLEEP_RETRY_MS;
         sleepOnNextExecution = false;
         uint32_t nightyNightMs = Default::getConfiguredOrDefaultMs(moduleConfig.telemetry.environment_update_interval,
                                                                    default_telemetry_broadcast_interval_secs);
@@ -334,6 +336,12 @@ int32_t EnvironmentTelemetryModule::runOnce()
             lastSentToPhone = millis();
         }
     }
+    if (sleepOnNextExecution) {
+        // Honor the pre-sleep grace period armed in sendTelemetry(): OSThread reschedules with
+        // this return value, which would otherwise override setIntervalFromNow() with the sensor
+        // polling interval (35 ms for BSEC2) and trigger deep sleep while the TX is still on air
+        return FIVE_SECONDS_MS;
+    }
     return min(sendToPhoneIntervalMs, result);
 }
 
@@ -635,7 +643,8 @@ bool EnvironmentTelemetryModule::sendTelemetry(NodeNum dest, bool phoneOnly)
     m.which_variant = meshtastic_Telemetry_environment_metrics_tag;
     m.time = getTime();
 
-    if (getEnvironmentTelemetry(&m)) {
+    bool validTelemetry = getEnvironmentTelemetry(&m);
+    if (validTelemetry) {
         LOG_INFO("Send: barometric_pressure=%f, current=%f, gas_resistance=%f, relative_humidity=%f, temperature=%f",
                  m.variant.environment_metrics.barometric_pressure, m.variant.environment_metrics.current,
                  m.variant.environment_metrics.gas_resistance, m.variant.environment_metrics.relative_humidity,
@@ -670,7 +679,7 @@ bool EnvironmentTelemetryModule::sendTelemetry(NodeNum dest, bool phoneOnly)
             LOG_INFO("Send packet to mesh");
             service->sendToMesh(p, RX_SRC_LOCAL, true);
 
-            if (config.device.role == meshtastic_Config_DeviceConfig_Role_SENSOR && config.power.is_power_saving) {
+            if (isPowerSavingSensor()) {
                 meshtastic_ClientNotification *notification = clientNotificationPool.allocZeroed();
                 notification->level = meshtastic_LogRecord_Level_INFO;
                 notification->time = getValidTime(RTCQualityFromNet);
@@ -679,14 +688,22 @@ bool EnvironmentTelemetryModule::sendTelemetry(NodeNum dest, bool phoneOnly)
                                                           default_telemetry_broadcast_interval_secs) /
                             1000U);
                 service->sendClientNotification(notification);
-                sleepOnNextExecution = true;
-                LOG_DEBUG("Start next execution in 5s, then sleep");
-                setIntervalFromNow(FIVE_SECONDS_MS);
             }
         }
-        return true;
     }
-    return false;
+
+    // Arm the pre-sleep sequence even when no valid reading was available this cycle (e.g. a
+    // BSEC2 call timing violation): a power-saving SENSOR node must still return to deep sleep,
+    // otherwise it stays awake until the next telemetry interval and drains its battery
+    if (!phoneOnly && isPowerSavingSensor()) {
+        if (!validTelemetry)
+            LOG_WARN("Environment telemetry unavailable this cycle, sleep without sending");
+        sleepOnNextExecution = true;
+        preflightSleepDeferrals = 0;
+        LOG_DEBUG("Start next execution in 5s, then sleep");
+        setIntervalFromNow(FIVE_SECONDS_MS);
+    }
+    return validTelemetry;
 }
 
 AdminMessageHandleResult EnvironmentTelemetryModule::handleAdminMessageForModule(const meshtastic_MeshPacket &mp,