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/redeem_cache.go

@@ -1,62 +1,62 @@
-package repository
-
-import (
-	"context"
-	"fmt"
-	"time"
-
-	"github.com/Wei-Shaw/sub2api/internal/service"
-	"github.com/redis/go-redis/v9"
-)
-
-const (
-	redeemRateLimitKeyPrefix = "redeem:ratelimit:"
-	redeemLockKeyPrefix      = "redeem:lock:"
-	redeemRateLimitDuration  = 24 * time.Hour
-)
-
-// redeemRateLimitKey generates the Redis key for redeem attempt rate limiting.
-func redeemRateLimitKey(userID int64) string {
-	return fmt.Sprintf("%s%d", redeemRateLimitKeyPrefix, userID)
-}
-
-// redeemLockKey generates the Redis key for redeem code locking.
-func redeemLockKey(code string) string {
-	return redeemLockKeyPrefix + code
-}
-
-type redeemCache struct {
-	rdb *redis.Client
-}
-
-func NewRedeemCache(rdb *redis.Client) service.RedeemCache {
-	return &redeemCache{rdb: rdb}
-}
-
-func (c *redeemCache) GetRedeemAttemptCount(ctx context.Context, userID int64) (int, error) {
-	key := redeemRateLimitKey(userID)
-	count, err := c.rdb.Get(ctx, key).Int()
-	if err == redis.Nil {
-		return 0, nil
-	}
-	return count, err
-}
-
-func (c *redeemCache) IncrementRedeemAttemptCount(ctx context.Context, userID int64) error {
-	key := redeemRateLimitKey(userID)
-	pipe := c.rdb.Pipeline()
-	pipe.Incr(ctx, key)
-	pipe.Expire(ctx, key, redeemRateLimitDuration)
-	_, err := pipe.Exec(ctx)
-	return err
-}
-
-func (c *redeemCache) AcquireRedeemLock(ctx context.Context, code string, ttl time.Duration) (bool, error) {
-	key := redeemLockKey(code)
-	return c.rdb.SetNX(ctx, key, 1, ttl).Result()
-}
-
-func (c *redeemCache) ReleaseRedeemLock(ctx context.Context, code string) error {
-	key := redeemLockKey(code)
-	return c.rdb.Del(ctx, key).Err()
-}
+package repository
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/service"
+	"github.com/redis/go-redis/v9"
+)
+
+const (
+	redeemRateLimitKeyPrefix = "redeem:ratelimit:"
+	redeemLockKeyPrefix      = "redeem:lock:"
+	redeemRateLimitDuration  = 24 * time.Hour
+)
+
+// redeemRateLimitKey generates the Redis key for redeem attempt rate limiting.
+func redeemRateLimitKey(userID int64) string {
+	return fmt.Sprintf("%s%d", redeemRateLimitKeyPrefix, userID)
+}
+
+// redeemLockKey generates the Redis key for redeem code locking.
+func redeemLockKey(code string) string {
+	return redeemLockKeyPrefix + code
+}
+
+type redeemCache struct {
+	rdb *redis.Client
+}
+
+func NewRedeemCache(rdb *redis.Client) service.RedeemCache {
+	return &redeemCache{rdb: rdb}
+}
+
+func (c *redeemCache) GetRedeemAttemptCount(ctx context.Context, userID int64) (int, error) {
+	key := redeemRateLimitKey(userID)
+	count, err := c.rdb.Get(ctx, key).Int()
+	if err == redis.Nil {
+		return 0, nil
+	}
+	return count, err
+}
+
+func (c *redeemCache) IncrementRedeemAttemptCount(ctx context.Context, userID int64) error {
+	key := redeemRateLimitKey(userID)
+	pipe := c.rdb.Pipeline()
+	pipe.Incr(ctx, key)
+	pipe.Expire(ctx, key, redeemRateLimitDuration)
+	_, err := pipe.Exec(ctx)
+	return err
+}
+
+func (c *redeemCache) AcquireRedeemLock(ctx context.Context, code string, ttl time.Duration) (bool, error) {
+	key := redeemLockKey(code)
+	return c.rdb.SetNX(ctx, key, 1, ttl).Result()
+}
+
+func (c *redeemCache) ReleaseRedeemLock(ctx context.Context, code string) error {
+	key := redeemLockKey(code)
+	return c.rdb.Del(ctx, key).Err()
+}