feat: expand companion platform, device controls, and memoir workflows

Add customer and operator login, BLE provisioning, device fleet controls, call memory, memoir generation, and refreshed family and maintenance portals. Include API contracts, migrations, firmware sources, tests, assets, and deployment documentation.

firmware/echoear-platform-agent/main/device_ota.h

@@ -0,0 +1,12 @@
+#pragma once
+#include "esp_err.h"
+#include <stdbool.h>
+#include <stdint.h>
+void device_ota_boot_guard(void);
+void device_ota_boot_ready(void);
+bool device_ota_supported(void);
+const char *device_ota_version(void);
+int64_t device_ota_version_code(void);
+void device_ota_poll(void);
+// MQTT is a wakeup only; the manifest is fetched over factory-authenticated TLS.
+void device_ota_request(const char *task_id);