feat: RFC 8054 COMPRESS DEFLATE wire compression + dep upgrades

[mjc]

Summary

• Implement RFC 8054 COMPRESS DEFLATE for proxy→backend connections: after authentication, the proxy negotiates deflate compression, wrapping the TCP stream in a DecompressStream codec that transparently compresses outbound commands and decompresses inbound responses. Configurable via compress (auto/require/disable) and compress_level (0-9).
• Upgrade dependencies: foyer 0.22, nix 0.31, rand 0.9, ratatui 0.30, sysinfo 0.38 with corresponding migration code.

Compression details

• Raw deflate (no zlib header) per RFC 8054 §2.2.2
• FlushCompress::Sync flush for interactive NNTP command/response
• poll_write/poll_flush with DrainState to avoid per-call allocations and handle partial inner writes
• Client→proxy traffic remains uncompressed
• Optional zlib-ng feature flag for SIMD-optimized compression (requires cmake)

Dependency upgrades

• foyer 0.21→0.22: BlockEngineBuilder→BlockEngineConfig, RuntimeOptions→Spawner, NoopIoEngineBuilder→NoopIoEngineConfig
• rand 0.8→0.9: thread_rng()→rng(), gen_range()→random_range()
• ratatui 0.29→0.30: Backend::Error associated type, added Send + Sync + 'static bound
• nix 0.30→0.31, sysinfo 0.37→0.38: no code changes needed

Test plan

• cargo check passes on each commit independently
• cargo test -p nntp-proxy --lib — 1240 tests pass on each commit
• cargo clippy --all-targets clean on each commit
• cargo fmt --check clean on each commit

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR implements RFC 8054 COMPRESS DEFLATE wire compression for proxy→backend connections and upgrades several key dependencies (foyer 0.21→0.22, nix 0.30→0.31, rand 0.8→0.9, ratatui 0.29→0.30, sysinfo 0.37→0.38).

Changes:

• Adds bidirectional deflate compression support using raw DEFLATE format (no zlib header) with automatic negotiation after authentication
• Implements DecompressStream wrapper with efficient poll-based async I/O, separate write/flush buffers, and bandwidth statistics
• Adds compress (auto/require/disable) and compress_level (0-9) configuration options per backend server
• Migrates foyer to use explicit runtime spawner instead of RuntimeOptions, updates rand API calls, and adds ratatui trait bounds

Reviewed changes

Copilot reviewed 22 out of 23 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/compression.rs	Complete rewrite: implements bidirectional deflate compression with poll-based I/O, buffer management, and comprehensive test coverage
src/pool/deadpool_connection.rs	Adds compression negotiation after auth, wraps streams in DecompressStream on 206 response
src/connection_error.rs	Adds CompressionRequired error variant for when compression is required but not supported
src/stream.rs	Adds CompressedPlain and CompressedTls enum variants and helper constructors
src/protocol/commands.rs	Adds COMPRESS_DEFLATE command constant
src/protocol/mod.rs	Re-exports COMPRESS_DEFLATE command
src/protocol/response.rs	Removes #[must_use] from as_u16() method
src/config/types.rs	Adds compress and compress_level fields to Server and ServerBuilder
src/config/loading.rs	Initializes new compression fields to None in environment parsing
src/session/retry.rs	Updates rand 0.9 API: thread_rng() → rng(), gen_range() → random_range()
src/cache/hybrid.rs	Migrates foyer 0.22: BlockEngineBuilder → BlockEngineConfig, creates explicit runtime, NoopIoEngineBuilder → NoopIoEngineConfig
src/tui/mod.rs	Adds Send + Sync + 'static bound on B::Error for ratatui 0.30 compatibility
tests/test_helpers.rs	Adds compress and compress_level fields to test config construction
tests/test_properties.proptest-regressions	Proptest regression cases for status code validation
src/proxy/mod.rs	Updates test configs with new compression fields
src/pool/prewarming.rs	Updates test configs with new compression fields
src/pool/provider.rs	Passes compression parameters through to TcpManager
scripts/profile*.sh	Adds --features zlib-ng flag for SIMD-optimized profiling builds
flake.nix	Adds cmake dependency required for zlib-ng feature
Cargo.toml	Upgrades dependencies and adds flate2 with rust_backend, pin-project-lite
Cargo.lock	Dependency lock file updates for all upgraded and new dependencies

[Copilot]

Pull request overview

Copilot reviewed 25 out of 26 changed files in this pull request and generated no new comments.