feat(region_pricing): 扩展非 token 统一计费字段，支持语音按字符/秒计费

- 新增 region_pricing.pricing_mode / price_unit / flat_price 字段
- 新增 migration 016_region_pricing_non_token_units.sql
- officialPricingRecord 新增 PricingMode/PriceUnit/FlatPrice 字段
- detectModality 新增 audio 模态检测（voice/audio/speech）
- providerMetadata 新增 BAAI/ByteDance/China Mobile 元数据
- import_mobile_cloud_pricing.go: 解析语音计费表（CosyVoice/SenseVoice）
  - CosyVoice: 2元/万字符 → pricingMode=flat, priceUnit=10k_characters
  - SenseVoice: 0.0007元/秒 → pricingMode=flat, priceUnit=second
- mobileCloudProviderName 新增 cosyvoice/sensevoice → Alibaba 映射
- cmd/server: modelResponse 新增 pricingMode/priceUnit/flatPrice，API 字段说明同步更新
- 新增 TestModelsHandlerReturnsFlatPricingFields 测试

scripts/import_mobile_cloud_pricing_test.go

@@ -0,0 +1,89 @@
+//go:build llm_script
+
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestResolveMobileCloudPricingArticle(t *testing.T) {
+	raw := `{"code":200,"data":{"children":[{"articleTitle":"其他文档","articleId":1,"articleContentPublished":"x"},{"children":[{"articleTitle":"预置模型服务-token按量计费","articleId":91592,"articleContentPublished":"64ec46cbfd7c535db501aff43df5a788"}]}]}}`
+	articleID, contentPublished, err := resolveMobileCloudPricingArticle(raw)
+	if err != nil {
+		t.Fatalf("resolveMobileCloudPricingArticle 返回错误: %v", err)
+	}
+	if articleID != 91592 || contentPublished != "64ec46cbfd7c535db501aff43df5a788" {
+		t.Fatalf("解析价格文章失败: articleID=%d contentPublished=%q", articleID, contentPublished)
+	}
+}
+
+func TestParseMobileCloudPricingHTMLBuildsRecords(t *testing.T) {
+	raw, err := os.ReadFile(filepath.Join("testdata", "mobile_cloud_pricing_sample.html"))
+	if err != nil {
+		t.Fatalf("读取 fixture 失败: %v", err)
+	}
+	records, err := parseMobileCloudPricingHTML(string(raw), "https://ecloud.10086.cn/op-help-center/doc/article/91592")
+	if err != nil {
+		t.Fatalf("parseMobileCloudPricingHTML 返回错误: %v", err)
+	}
+	if len(records) != 8 {
+		t.Fatalf("期望 8 条移动云价格记录，实际 %d", len(records))
+	}
+	recordMap := make(map[string]officialPricingRecord, len(records))
+	for _, record := range records {
+		recordMap[record.ModelID] = record
+	}
+	if recordMap["mobile-cloud-huabei-huhehaote-minimax-m2-5"].Region != "华北-呼和浩特" {
+		t.Fatalf("华北 MiniMax region 错误: %+v", recordMap["mobile-cloud-huabei-huhehaote-minimax-m2-5"])
+	}
+	if recordMap["mobile-cloud-huabei-huhehaote-deepseek-v3-0324"].InputPrice != 2 || recordMap["mobile-cloud-huabei-huhehaote-deepseek-v3-0324"].OutputPrice != 8 {
+		t.Fatalf("DeepSeek-V3-0324 价格错误: %+v", recordMap["mobile-cloud-huabei-huhehaote-deepseek-v3-0324"])
+	}
+	if recordMap["mobile-cloud-huabei-huhehaote-qwq-32b"].ProviderName != "Qwen" || recordMap["mobile-cloud-huabei-huhehaote-qwq-32b"].OutputPrice != 6 {
+		t.Fatalf("QwQ-32B provider/价格错误: %+v", recordMap["mobile-cloud-huabei-huhehaote-qwq-32b"])
+	}
+	if recordMap["mobile-cloud-huabei-huhehaote-bge-m3"].ProviderName != "BAAI" || recordMap["mobile-cloud-huabei-huhehaote-bge-m3"].InputPrice != 0.5 || recordMap["mobile-cloud-huabei-huhehaote-bge-m3"].OutputPrice != 0.5 {
+		t.Fatalf("bge-m3 平价 token 记录错误: %+v", recordMap["mobile-cloud-huabei-huhehaote-bge-m3"])
+	}
+	cosyVoice, ok := recordMap["mobile-cloud-huabei-huhehaote-cosyvoice"]
+	if !ok {
+		t.Fatalf("缺少 CosyVoice 语音计费记录")
+	}
+	if cosyVoice.ProviderName != "Alibaba" || cosyVoice.Modality != "audio" || cosyVoice.PricingMode != "flat" || cosyVoice.FlatPrice != 2 || cosyVoice.PriceUnit != "10k_characters" {
+		t.Fatalf("CosyVoice 语音计费记录错误: %+v", cosyVoice)
+	}
+	senseVoice, ok := recordMap["mobile-cloud-huabei-huhehaote-sensevoice"]
+	if !ok {
+		t.Fatalf("缺少 SenseVoice 语音计费记录")
+	}
+	if senseVoice.ProviderName != "Alibaba" || senseVoice.Modality != "audio" || senseVoice.PricingMode != "flat" || senseVoice.FlatPrice != 0.0007 || senseVoice.PriceUnit != "second" {
+		t.Fatalf("SenseVoice 语音计费记录错误: %+v", senseVoice)
+	}
+}
+
+func TestRunMobileCloudPricingImportDryRunPrintsSummary(t *testing.T) {
+	var out bytes.Buffer
+	err := runMobileCloudPricingImport(mobileCloudPricingImportConfig{
+		OutlineTreeURL: defaultMobileCloudOutlineTreeURL,
+		Fixture:        filepath.Join("testdata", "mobile_cloud_pricing_sample.html"),
+		DryRun:         true,
+	}, nil, &out)
+	if err != nil {
+		t.Fatalf("runMobileCloudPricingImport 返回错误: %v", err)
+	}
+	output := out.String()
+	for _, want := range []string{
+		"source=mobile-cloud-pricing-import",
+		"models=8",
+		"operator=Mobile Cloud",
+		"dry_run=true",
+	} {
+		if !strings.Contains(output, want) {
+			t.Fatalf("输出缺少 %q，实际: %q", want, output)
+		}
+	}
+}