Fix/getobjectlength (#920)

* fix getobject content length resp

* Fix regression in exception handling for non-existent key with enhanced compression predicate and metadata improvements (#915)

* Initial plan

* Fix GetObject regression by excluding error responses from compression

The issue was that CompressionLayer was attempting to compress error responses,
which could cause Content-Length header mismatches. By excluding 4xx and 5xx
responses from compression, we ensure error responses (like NoSuchKey) are sent
correctly without body truncation.

Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>

* Enhance NoSuchKey fix with improved compression predicate and comprehensive tests

- Enhanced ShouldCompress predicate with size-based exclusion (< 256 bytes)
- Added detailed documentation explaining the compression logic
- Added debug logging for better observability
- Created comprehensive test suite with 4 test cases:
  - test_get_deleted_object_returns_nosuchkey
  - test_head_deleted_object_returns_nosuchkey
  - test_get_nonexistent_object_returns_nosuchkey
  - test_multiple_gets_deleted_object
- Added extensive inline documentation and comments
- Created docs/fix-nosuchkey-regression.md with full analysis

Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>

* Add compression best practices documentation

Added comprehensive guide covering:
- Best practices for HTTP response compression
- Common pitfalls and solutions
- Performance considerations and trade-offs
- Testing guidelines and examples
- Monitoring and alerting recommendations
- Migration guide for existing services

Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>

* fix

* fmt

* fmt

* Fix/objectdelete (#917)

* fix getobject content length resp

* fix delete object

---------

Co-authored-by: houseme <housemecn@gmail.com>

* Add comprehensive analysis of NoSuchKey fix and related improvements

Created detailed documentation analyzing:
- HTTP compression layer fix (primary issue)
- Content-length calculation fix from PR #917
- Delete object metadata fixes from PR #917
- How all components work together
- Complete scenario walkthrough
- Performance impact analysis
- Testing strategy and deployment checklist

This ties together all the changes in the PR branch including the merged
improvements from PR #917.

Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>

* replace `once_cell` to `std`

* fmt

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>
Co-authored-by: houseme <housemecn@gmail.com>
Co-authored-by: weisd <im@weisd.in>

* fmt

---------

Co-authored-by: weisd <weishidavip@163.com>
Co-authored-by: Copilot <198982749+Copilot@users.noreply.github.com>
Co-authored-by: houseme <4829346+houseme@users.noreply.github.com>
Co-authored-by: weisd <im@weisd.in>

Cargo.lock

@@ -7290,7 +7290,6 @@ dependencies = [
  "bytes",
  "crossbeam-queue",
  "futures",
- "once_cell",
  "parking_lot",
  "rustfs-protos",
  "serde",