feat(server): implement chat file TTL cleanup and enhance JPush vendor channel support

Add FileCleanupWorker for automatic expiration of chat files with configurable retention period and batch processing. Files uploaded via `/api/v1/uploads/files` are tracked in `uploaded_files` table with expiration timestamps, then deleted from S3 and database upon expiry. Expired file URLs are injected as `"expired": true` in message responses.

Extend JPush push notification configuration with vendor-specific channel_id support (xiaomi, huawei, oppo, vivo, meizu, honor, fcm) for differentiating system vs chat notifications. Add iOS APNs thread-id grouping configuration for notification categorization.

internal/repository/uploaded_file_repo.go

@@ -0,0 +1,91 @@
+package repository
+
+import (
+	"context"
+	"time"
+
+	"with_you/internal/model"
+
+	"gorm.io/gorm"
+)
+
+// UploadedFileRepository 文件上传记录仓储接口
+type UploadedFileRepository interface {
+	// Create 写入一条上传记录
+	Create(ctx context.Context, file *model.UploadedFile) error
+	// GetByURL 按 URL 查询记录（DTO 失效标记用）
+	GetByURL(ctx context.Context, url string) (*model.UploadedFile, error)
+	// ListPendingCleanup 取 created_at < before 且 expired=false 的记录，分批
+	ListPendingCleanup(ctx context.Context, before time.Time, limit int) ([]model.UploadedFile, error)
+	// MarkExpired 标记某条记录已清理
+	MarkExpired(ctx context.Context, id uint, at time.Time) error
+	// GetExpiredURLSet 批量查询已标记过期的 URL 集合（DTO 注入用）
+	// 注意：这是全量扫描 expired=true 的记录，适用于上传量不大的场景；
+	// 若 uploaded_files 表增长过大，可改为按时间窗口分页。
+	GetExpiredURLSet(ctx context.Context) (map[string]struct{}, error)
+}
+
+// uploadedFileRepository 文件上传记录仓储实现
+type uploadedFileRepository struct {
+	db *gorm.DB
+}
+
+// NewUploadedFileRepository 创建文件上传记录仓储
+func NewUploadedFileRepository(db *gorm.DB) UploadedFileRepository {
+	return &uploadedFileRepository{db: db}
+}
+
+// Create 写入一条上传记录
+func (r *uploadedFileRepository) Create(ctx context.Context, file *model.UploadedFile) error {
+	return r.db.WithContext(ctx).Create(file).Error
+}
+
+// GetByURL 按 URL 查询记录
+func (r *uploadedFileRepository) GetByURL(ctx context.Context, url string) (*model.UploadedFile, error) {
+	var file model.UploadedFile
+	if err := r.db.WithContext(ctx).Where("url = ?", url).First(&file).Error; err != nil {
+		return nil, err
+	}
+	return &file, nil
+}
+
+// ListPendingCleanup 取待清理记录
+func (r *uploadedFileRepository) ListPendingCleanup(ctx context.Context, before time.Time, limit int) ([]model.UploadedFile, error) {
+	if limit <= 0 {
+		limit = 100
+	}
+	var files []model.UploadedFile
+	err := r.db.WithContext(ctx).
+		Where("created_at < ? AND expired = ?", before, false).
+		Order("created_at ASC").
+		Limit(limit).
+		Find(&files).Error
+	return files, err
+}
+
+// MarkExpired 标记已清理
+func (r *uploadedFileRepository) MarkExpired(ctx context.Context, id uint, at time.Time) error {
+	return r.db.WithContext(ctx).Model(&model.UploadedFile{}).
+		Where("id = ?", id).
+		Updates(map[string]any{
+			"expired":    true,
+			"expired_at": at,
+		}).Error
+}
+
+// GetExpiredURLSet 批量查询已过期 URL 集合
+func (r *uploadedFileRepository) GetExpiredURLSet(ctx context.Context) (map[string]struct{}, error) {
+	var urls []string
+	err := r.db.WithContext(ctx).
+		Model(&model.UploadedFile{}).
+		Where("expired = ?", true).
+		Pluck("url", &urls).Error
+	if err != nil {
+		return nil, err
+	}
+	set := make(map[string]struct{}, len(urls))
+	for _, u := range urls {
+		set[u] = struct{}{}
+	}
+	return set, nil
+}