新增配置调试功能：支持输出完整配置项与环境变量覆盖详情，调整 cron.daily_spec 默认值

internal/config/config_test.go

@@ -1,6 +1,9 @@
 package config
 
 import (
+	"fmt"
+	"os"
+	"strings"
 	"testing"
 )
 
@@ -19,3 +22,46 @@ func TestDefaultConfig(t *testing.T) {
 		t.Errorf("Expected DB type sqlite, got %s", cfg.DB.Type)
 	}
 }
+
+func TestDebugFunctions(t *testing.T) {
+	// 设置一个环境变量
+	os.Setenv("BINGPAPER_SERVER_PORT", "9999")
+	defer os.Unsetenv("BINGPAPER_SERVER_PORT")
+
+	err := Init("")
+	if err != nil {
+		t.Fatalf("Failed to init config: %v", err)
+	}
+
+	settings := GetAllSettings()
+	serverCfg, ok := settings["server"].(map[string]interface{})
+	if !ok {
+		t.Fatalf("Expected server config map, got %v", settings["server"])
+	}
+
+	// Viper numbers in AllSettings are often int
+	portValue := serverCfg["port"]
+	// 允许不同的数字类型，因为 viper 内部实现可能变化
+	portStr := fmt.Sprintf("%v", portValue)
+	if portStr != "9999" {
+		t.Errorf("Expected port 9999 in settings, got %v (%T)", portValue, portValue)
+	}
+
+	overrides := GetEnvOverrides()
+	found := false
+	for _, o := range overrides {
+		if strings.Contains(o, "server.port") && strings.Contains(o, "9999") {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Errorf("Expected server.port override in %v", overrides)
+	}
+
+	// 验证格式化输出
+	formatted := GetFormattedSettings()
+	if !strings.Contains(formatted, "server.port: 9999") {
+		t.Errorf("Expected formatted settings to contain server.port: 9999, got %s", formatted)
+	}
+}