Add M5Stack Cardputer Advanced (Cap LoRa-1262) companion support

Adds full companion firmware support for the M5Stack Cardputer Advanced
with Cap LoRa-1262 (SX1262, EU868). Tested and verified building against
v1.15.0 on hardware.

New files:
- boards/m5stack_cardputer.json: PlatformIO board definition (ESP32-S3, 8MB flash/PSRAM)
- variants/m5stack_cardputer/: Hardware variant (SX1262 pinout, TCXO, GPS support)
- src/helpers/ui/M5CardputerDisplay.{h,cpp}: LVGL display driver for Cardputer screen
- examples/companion_radio/ui-keyboard/: Keyboard-driven UI (contacts, channels, chat, settings)
- examples/companion_radio/UITask.h: Dispatcher selecting ui-keyboard when HEADLESS_UI=1

Companion radio changes:
- NodePrefs: add screen_timeout_seconds (0=never, 10/30/60/120/300s)
- MyMesh: expose saveContacts(), saveChannels(), factoryReset() as public
- MyMesh: add queueOutgoingMessageForBLE() for outgoing message BLE sync

Build target: env:M5stack_cardputer_cap_lora1262_companion
RAM: 49.9% | Flash: 42.2% of 8MB partition

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 2 people

boards/m5stack_cardputer.json

@@ -0,0 +1,41 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "esp32s3_out.ld",
+      "partitions": "default_8MB.csv",
+      "memory_type": "qio_opi"
+    },
+    "core": "esp32",
+    "extra_flags": [
+      "-DARDUINO_M5STACK_CARDPUTER",
+      "-DBOARD_HAS_PSRAM",
+      "-DARDUINO_USB_CDC_ON_BOOT=1",
+      "-DARDUINO_USB_MODE=1",
+      "-DARDUINO_RUNNING_CORE=1",
+      "-DARDUINO_EVENT_RUNNING_CORE=1"
+    ],
+    "f_cpu": "240000000L",
+    "f_flash": "80000000L",
+    "flash_mode": "qio",
+    "hwids": [["0x303A", "0x1001"]],
+    "mcu": "esp32s3",
+    "variant": "esp32s3"
+  },
+  "connectivity": ["wifi", "bluetooth"],
+  "debug": {
+    "default_tool": "esp-builtin",
+    "onboard_tools": ["esp-builtin"],
+    "openocd_target": "esp32s3.cfg"
+  },
+  "frameworks": ["arduino", "espidf"],
+  "name": "M5Stack Cardputer-Adv (8M Flash 8M PSRAM)",
+  "upload": {
+    "flash_size": "8MB",
+    "maximum_ram_size": 327680,
+    "maximum_size": 8388608,
+    "require_upload_port": true,
+    "speed": 1500000
+  },
+  "url": "https://shop.m5stack.com/products/m5stack-cardputer-adv",
+  "vendor": "M5Stack"
+}

examples/companion_radio/MyMesh.cpp

@@ -2191,3 +2191,44 @@ bool MyMesh::advert() {
     return false;
   }
 }
+
+void MyMesh::queueOutgoingMessageForBLE(const ContactInfo* contact, const ChannelDetails* channel,
+                                         const char* from_name, const char* text, uint32_t timestamp) {
+  int i = 0;
+  uint8_t frame[MAX_FRAME_SIZE];
+  bool is_channel = (channel != NULL);
+
+  if (is_channel) {
+    if (app_target_ver >= 3) {
+      frame[i++] = RESP_CODE_CHANNEL_MSG_RECV_V3;
+      frame[i++] = 0; frame[i++] = 0; frame[i++] = 0;
+    } else {
+      frame[i++] = RESP_CODE_CHANNEL_MSG_RECV;
+    }
+    uint8_t channel_idx = findChannelIdx(channel->channel);
+    frame[i++] = channel_idx;
+    frame[i++] = 0xFF;
+    frame[i++] = TXT_TYPE_PLAIN;
+    memcpy(&frame[i], &timestamp, 4); i += 4;
+    int name_len = strlen(from_name);
+    if (name_len > 30) name_len = 30;
+    memcpy(&frame[i], from_name, name_len); i += name_len;
+    frame[i++] = ':'; frame[i++] = ' ';
+  } else if (contact) {
+    if (app_target_ver >= 3) {
+      frame[i++] = RESP_CODE_CONTACT_MSG_RECV_V3;
+      frame[i++] = 0; frame[i++] = 0; frame[i++] = 0;
+    } else {
+      frame[i++] = RESP_CODE_CONTACT_MSG_RECV;
+    }
+    memcpy(&frame[i], contact->id.pub_key, 6); i += 6;
+    frame[i++] = 0xFF;
+    frame[i++] = TXT_TYPE_PLAIN;
+    memcpy(&frame[i], &timestamp, 4); i += 4;
+  }
+
+  int text_len = strlen(text);
+  if (i + text_len > MAX_FRAME_SIZE) text_len = MAX_FRAME_SIZE - i;
+  memcpy(&frame[i], text, text_len); i += text_len;
+  addToOfflineQueue(frame, i);
+}

examples/companion_radio/MyMesh.h

@@ -100,6 +100,12 @@ class MyMesh : public BaseChatMesh, public DataStoreHost {
   bool advert();
   void enterCLIRescue();
 
+  void factoryReset() { _store->formatFileSystem(); }
+  void saveContacts() { _store->saveContacts(this); }
+  void saveChannels() { _store->saveChannels(this); }
+  void queueOutgoingMessageForBLE(const ContactInfo* contact, const ChannelDetails* channel,
+                                  const char* from_name, const char* text, uint32_t timestamp);
+
   int  getRecentlyHeard(AdvertPath dest[], int max_num);
 
 protected:
@@ -196,9 +202,7 @@ class MyMesh : public BaseChatMesh, public DataStoreHost {
   void checkSerialInterface();
   bool isValidClientRepeatFreq(uint32_t f) const;
 
-  // helpers, short-cuts
-  void saveChannels() { _store->saveChannels(this); }
-  void saveContacts() { _store->saveContacts(this); }
+  // helpers, short-cuts (public versions above)
 
   DataStore* _store;
   NodePrefs _prefs;

examples/companion_radio/NodePrefs.h

@@ -25,6 +25,7 @@ struct NodePrefs {  // persisted to file
   uint32_t ble_pin;
   uint8_t  advert_loc_policy;
   uint8_t  buzzer_quiet;
+  uint16_t screen_timeout_seconds;  // 0=Never, 10, 30, 60, 120, 300
   uint8_t  gps_enabled;      // GPS enabled flag (0=disabled, 1=enabled)
   uint32_t gps_interval;     // GPS read interval in seconds
   uint8_t autoadd_config;    // bitmask for auto-add contacts config

examples/companion_radio/UITask.h

@@ -0,0 +1,8 @@
+#pragma once
+
+// Conditional include based on UI mode
+#ifdef HEADLESS_UI
+  #include "ui-keyboard/UITask.h"
+#else
+  #include "ui-new/UITask.h"
+#endif