feat(build): 优化构建配置并引入日志分级系统

- 将优化级别从balanced调整为size，减少Flash占用
- 添加hardfault.cpp文件以增强故障诊断能力
- 关闭RTTI和异常处理以移除libcppabi运行时（节省约2.5KB Flash）
- 添加链接器参数输出未引用段与总量报告用于Flash尺寸分析

refactor(logging): 统一日志输出并实现编译时日志分级

- 将printf调用替换为模块化的日志宏（ECAT_LOGI、CAN_LOGI等）
- 实现CONFIG_*_LOG_ENABLE编译开关控制各模块INFO级日志
- 错误和关键事件使用LOG_ERR恒定保留，其他日志可编译时裁剪
- 保持原有日志内容不变，但支持链接器自动回收未使用的格式字符串

GD32E508_DCU_APP/main.cpp

@@ -19,13 +19,13 @@
  */
 void App::printBanner() const
 {
-    printf("\r\n");
-    printf("========================================\r\n");
-    printf("  GD32E508 DCU APP started OK\r\n");
-    printf("  System clock: 180 MHz\r\n");
-    printf("  Build: " __DATE__ " " __TIME__ "\r\n");
-    printf("========================================\r\n");
-    printf("[APP] APP running, uptime_sec=0\r\n");
+    APP_LOGI("\r\n");
+    APP_LOGI("========================================\r\n");
+    APP_LOGI("  GD32E508 DCU APP started OK\r\n");
+    APP_LOGI("  System clock: 180 MHz\r\n");
+    APP_LOGI("  Build: " __DATE__ " " __TIME__ "\r\n");
+    APP_LOGI("========================================\r\n");
+    APP_LOGI("[APP] APP running, uptime_sec=0\r\n");
 }
 
 /**
@@ -37,12 +37,12 @@ void App::printBanner() const
  */
 int App::run()
 {
-    printf("[APP] >>> main() entered, SystemCoreClock=%lu\r\n", (unsigned long)SystemCoreClock);
-    printf("[APP] >>> calling AppInitializer::init()...\r\n");
+    APP_LOGI("[APP] >>> main() entered, SystemCoreClock=%lu\r\n", (unsigned long)SystemCoreClock);
+    APP_LOGI("[APP] >>> calling AppInitializer::init()...\r\n");
     AppInitializer::init();
-    printf("[APP] >>> init done, calling TaskRunner::init()...\r\n");
+    APP_LOGI("[APP] >>> init done, calling TaskRunner::init()...\r\n");
     TaskRunner::init();
-    printf("[APP] >>> TaskRunner ready, entering main loop\r\n");
+    APP_LOGI("[APP] >>> TaskRunner ready, entering main loop\r\n");
     printBanner();
 
     while(1) {