feat: complete assembly mesh relay control path

- synchronize STM8 application and external flash layout updates\n- add assembly bootloader and assembly application test projects\n- add UART1 interrupt receive ring buffer\n- parse JDY-28M Mesh outer frames and source addresses\n- add CRC-16/MODBUS validation\n- implement relay control command 0x01 and response 0x81\n- support unicast and broadcast relay control frames\n- update host protocol, OTA documents, and serial tools

STM8_Test/Makefile

@@ -0,0 +1,45 @@
+# STM8S003F3P6TR PB5独立LED测试工程。
+# 本工程不包含Bootloader；测试主程序按0x8500链接，用于和汇编Bootloader合并。
+
+PROJECT := pb5_led_test
+BUILD_DIR := build
+CC := sdcc
+PACKIHX := packihx
+
+CFLAGS := -mstm8 --std-c99 --opt-code-size -Iinclude
+LDFLAGS := -mstm8 --out-fmt-ihx --code-loc 0x8000
+APP_LDFLAGS := -mstm8 --out-fmt-ihx --code-loc 0x8500
+
+OBJECT := $(BUILD_DIR)/main.rel
+IHX := $(BUILD_DIR)/$(PROJECT).ihx
+HEX := $(BUILD_DIR)/$(PROJECT).hex
+APP_IHX := $(BUILD_DIR)/$(PROJECT)_app.ihx
+APP_HEX := $(BUILD_DIR)/$(PROJECT)_app.hex
+
+.PHONY: all app clean
+
+all: app
+
+# 生成供Bootloader跳转测试使用的主程序镜像，链接地址必须为0x8500。
+app: $(APP_HEX)
+
+$(APP_HEX): $(APP_IHX)
+	$(PACKIHX) $< > $@
+
+$(APP_IHX): $(OBJECT)
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(APP_LDFLAGS) -o $@ $<
+
+$(HEX): $(IHX)
+	$(PACKIHX) $< > $@
+
+$(IHX): $(OBJECT)
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(LDFLAGS) -o $@ $<
+
+$(OBJECT): src/main.c
+	@mkdir -p $(BUILD_DIR)
+	$(CC) $(CFLAGS) -c $< -o $@
+
+clean:
+	rm -rf $(BUILD_DIR)