c3464d692e
- Introduced coalescing logic in `coalescing.go` to handle concurrent identical upstream fetches, including a state machine and response buffering for improved performance. - Implemented a new cache file format in `format.go`, supporting serialization and deserialization of HTTP responses, along with range request handling. - Developed an HTTP handler in `handler.go` to manage requests, including special endpoint handling and metrics reporting. - Added rate limiting functionality in `ratelimit.go` to control per-client and global request rates, enhancing security and performance. - Created service management capabilities in `service.go` to define and manage cacheable services, including user-agent detection. - Updated tests in `steamcache_test.go` to cover new functionalities, ensuring robustness and reliability across the codebase.