feat: 品牌重命名 Sub2API -> TianShuAPI

- 前端: 所有界面显示、i18n 文本、组件中的品牌名称
- 后端: 服务层、设置默认值、邮件模板、安装向导
- 数据库: 迁移脚本注释
- 保持功能完全一致，仅更改品牌名称

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

backend/internal/repository/pricing_service.go

@@ -1,78 +1,78 @@
-package repository
-
-import (
-	"context"
-	"fmt"
-	"io"
-	"net/http"
-	"strings"
-	"time"
-
-	"github.com/Wei-Shaw/sub2api/internal/pkg/httpclient"
-	"github.com/Wei-Shaw/sub2api/internal/service"
-)
-
-type pricingRemoteClient struct {
-	httpClient *http.Client
-}
-
-func NewPricingRemoteClient() service.PricingRemoteClient {
-	sharedClient, err := httpclient.GetClient(httpclient.Options{
-		Timeout: 30 * time.Second,
-	})
-	if err != nil {
-		sharedClient = &http.Client{Timeout: 30 * time.Second}
-	}
-	return &pricingRemoteClient{
-		httpClient: sharedClient,
-	}
-}
-
-func (c *pricingRemoteClient) FetchPricingJSON(ctx context.Context, url string) ([]byte, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return nil, err
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	if resp.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("HTTP %d", resp.StatusCode)
-	}
-
-	return io.ReadAll(resp.Body)
-}
-
-func (c *pricingRemoteClient) FetchHashText(ctx context.Context, url string) (string, error) {
-	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
-	if err != nil {
-		return "", err
-	}
-
-	resp, err := c.httpClient.Do(req)
-	if err != nil {
-		return "", err
-	}
-	defer func() { _ = resp.Body.Close() }()
-
-	if resp.StatusCode != http.StatusOK {
-		return "", fmt.Errorf("HTTP %d", resp.StatusCode)
-	}
-
-	body, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return "", err
-	}
-
-	// 哈希文件格式：hash  filename 或者纯 hash
-	hash := strings.TrimSpace(string(body))
-	parts := strings.Fields(hash)
-	if len(parts) > 0 {
-		return parts[0], nil
-	}
-	return hash, nil
-}
+package repository
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/httpclient"
+	"github.com/Wei-Shaw/sub2api/internal/service"
+)
+
+type pricingRemoteClient struct {
+	httpClient *http.Client
+}
+
+func NewPricingRemoteClient() service.PricingRemoteClient {
+	sharedClient, err := httpclient.GetClient(httpclient.Options{
+		Timeout: 30 * time.Second,
+	})
+	if err != nil {
+		sharedClient = &http.Client{Timeout: 30 * time.Second}
+	}
+	return &pricingRemoteClient{
+		httpClient: sharedClient,
+	}
+}
+
+func (c *pricingRemoteClient) FetchPricingJSON(ctx context.Context, url string) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("HTTP %d", resp.StatusCode)
+	}
+
+	return io.ReadAll(resp.Body)
+}
+
+func (c *pricingRemoteClient) FetchHashText(ctx context.Context, url string) (string, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("HTTP %d", resp.StatusCode)
+	}
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	// 哈希文件格式：hash  filename 或者纯 hash
+	hash := strings.TrimSpace(string(body))
+	parts := strings.Fields(hash)
+	if len(parts) > 0 {
+		return parts[0], nil
+	}
+	return hash, nil
+}