Gate every firmware build on runtime RAM and share nRF52 mOTA storage

src/helpers/ota/OtaCli.cpp

@@ -673,7 +673,7 @@ bool handle_ota_command(const char* command, char* reply, mesh::MainBoard& board
     const bool discarded = !was_folder && !was_sd_archive &&
                            c.fetch_store.discard();
     // Fetch cancellation and serving are independent. In particular, a
-    // manual ESP32 serve view can point into serve_buf, so leave the manager
+    // manual serve view can point into serve_buf, so leave the manager
     // view and its caller-owned buffer intact until `ota dev clear` (which
     // detaches the view before releasing the buffer).
     c.session_started_ms = 0;

src/helpers/ota/OtaContext.h

@@ -105,10 +105,10 @@ struct OtaContext {
   OtaStoreRam<OTA_FETCH_BUF_SIZE> fetch_store;
 #endif
   SignerAllowlist allow;
-#if defined(ESP32_PLATFORM)
-  // Manual `ota dev stage` is a diagnostic path. Reserving its full buffer in
-  // .bss prevents high-capacity classic ESP32 images from linking, even when
-  // the command is never used, so allocate it only while a manual stage exists.
+#if defined(ESP32_PLATFORM) || (defined(NRF52_PLATFORM) && !defined(OTA_SEEDER_ONLY))
+  // Manual `ota dev stage` is a diagnostic path. Keep its buffer out of
+  // startup RAM on ESP32 and nRF52 receivers; normal mOTA uses the staging
+  // store. A failed allocation is reported by the CLI before any write.
   uint8_t* serve_buf = nullptr;
   bool ensureServeBuffer() {
     if (!serve_buf) serve_buf = static_cast<uint8_t*>(malloc(OTA_SERVE_BUF_SIZE));

src/helpers/ota/OtaManager.h

@@ -3,6 +3,7 @@
 #include <stdint.h>
 #include <stddef.h>
 #include "OtaFormat.h"
+#include "OtaMemoryPolicy.h"
 #include "OtaProtocol.h"
 #include "OtaByteIO.h"
 #include "OtaStore.h"

src/helpers/ota/OtaMemoryPolicy.h

@@ -0,0 +1,9 @@
+#pragma once
+
+// Full nRF52 Companions stream host-provided firmware and need no permanent
+// mOTA workspace. Apply the same policy to build.sh and direct PlatformIO builds.
+#if defined(NRF52_PLATFORM) && defined(OTA_SEEDER_ONLY) && defined(COMPANION_RADIO_FULL)
+#ifndef OTA_SHARED_COMPANION_QUEUE
+#define OTA_SHARED_COMPANION_QUEUE 1
+#endif
+#endif