feat(imports): add real pricing and subscription collectors

Add plan catalog and subscription schema support, seed baselines, and real importers for core domestic subscriptions plus stable official pricing sources.

This commit also hardens the shared fetch layers so the importers can support live collection and database writes instead of relying on manual placeholders alone.

scripts/import_360_pricing_test.go

@@ -0,0 +1,55 @@
+//go:build llm_script
+
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestParse360PricingCatalogBuildsRecords(t *testing.T) {
+	raw, err := os.ReadFile(filepath.Join("testdata", "platform360_pricing_sample.txt"))
+	if err != nil {
+		t.Fatalf("读取 fixture 失败: %v", err)
+	}
+
+	records, err := parse360PricingCatalog(string(raw))
+	if err != nil {
+		t.Fatalf("parse360PricingCatalog 返回错误: %v", err)
+	}
+	if len(records) != 4 {
+		t.Fatalf("期望 4 条 360 价格记录，实际 %d", len(records))
+	}
+	if records[0].ModelID != "360-deepseek-deepseek-v4-flash" {
+		t.Fatalf("首条 modelID 错误: %q", records[0].ModelID)
+	}
+	if records[1].ContextLength != 1000000 {
+		t.Fatalf("第二条上下文长度错误: %d", records[1].ContextLength)
+	}
+}
+
+func TestRun360PricingImportDryRunPrintsSummary(t *testing.T) {
+	var out bytes.Buffer
+	err := run360PricingImport(platform360PricingImportConfig{
+		URL:     default360PricingURL,
+		Fixture: filepath.Join("testdata", "platform360_pricing_sample.txt"),
+		DryRun:  true,
+	}, nil, &out)
+	if err != nil {
+		t.Fatalf("run360PricingImport 返回错误: %v", err)
+	}
+	output := out.String()
+	for _, want := range []string{
+		"source=360-pricing-import",
+		"models=4",
+		"operator=360 Open Platform",
+		"dry_run=true",
+	} {
+		if !strings.Contains(output, want) {
+			t.Fatalf("输出缺少 %q，实际: %q", want, output)
+		}
+	}
+}