- Added `Export` method in `database/database.go` to export events to an io.Writer
- Implemented detailed logic for exporting all or specific pubkeys' events
- Removed placeholder `Export` function with TODO comment from `database/database.go`
- Updated error handling in `handleReq.go` and `publisher.go` by using `err != nil` instead of `chk.E(err)`
- Added more detailed logging in privilege check conditions in both `publisher.go` and `handleReq.go`
- Introduced new imports such as `"fmt"` in `connection.go` for improved error message formatting
- Created a new file `export.go` under the `database` package with complete implementation of export functionality
