feat(discovery): complete Phase 5 - Discovery & NAT Traversal

Sprint 5.5 - Integration & Testing (13 SP)

New Components:
- DiscoveryManager: Unified manager orchestrating DHT, NAT, and Relay
- DiscoveryConfig: Complete configuration for discovery system
- PeerConnection: Connection result with type classification
- ConnectionType: Direct, HolePunched, or Relayed connections
- DiscoveryState: Running state tracking (Stopped, Starting, Running, Stopping)
- DiscoveryError: Comprehensive error types for discovery operations

Implementation:
- End-to-end connection flow: DHT lookup → ICE candidates → direct → hole punch → relay
- Automatic fallback hierarchy for connection establishment
- NAT detection integration (optional, configurable)
- STUN server configuration for ICE candidate gathering
- Relay server management with DERP-style fallback
- Thread-safe state management with RwLock
- Graceful lifecycle management (start/shutdown)

Testing:
- 15 comprehensive integration tests
- Manager lifecycle and state transitions
- Configuration with bootstrap nodes and relay servers
- NAT detection enabled/disabled scenarios
- Connection type validation and error handling
- Concurrent peer discovery
- Timeout configuration
- Multiple manager instances

Documentation:
- phase-5-discovery.md: Sprint 5.5 complete, all tasks documented
- CHANGELOG.md: Phase 5 completion entry
- README.md: Updated test counts (622), added Phase 5 to completed components
- CLAUDE.local.md: Phase 5 completion status

Quality Gates:
- All tests passing (622 total, +15 new integration tests)
- Clippy clean (zero warnings)
- Formatting clean (cargo fmt)

Phase 5 Complete: 123/123 SP (100%)
Total Progress: 511/789 SP (65%)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: doublegate

CHANGELOG.md

@@ -9,6 +9,36 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+**Phase 5 Sprint 5.5: Integration & Testing - PHASE 5 COMPLETE (2025-11-30):**
+- Implemented unified `DiscoveryManager` for seamless peer discovery
+  - Orchestrates DHT, NAT traversal, and relay infrastructure
+  - End-to-end connection flow: DHT lookup → direct → hole punch → relay fallback
+  - Configuration system with `DiscoveryConfig` and `RelayInfo`
+  - State management (`DiscoveryState`: Stopped, Starting, Running, Stopping)
+  - Connection type tracking (`ConnectionType`: Direct, HolePunched, Relayed)
+  - DHT bootstrap with configurable bootstrap nodes
+  - Relay server connection and automatic registration
+  - NAT type detection integration with STUN
+  - 8 public methods + 6 helper methods
+- Added comprehensive integration tests (15 tests)
+  - Discovery manager lifecycle (creation, start, shutdown)
+  - Configuration with bootstrap nodes, STUN servers, relay servers
+  - NAT detection enable/disable scenarios
+  - Relay enable/disable scenarios
+  - Connection type variants and display
+  - Peer discovery flow (DHT lookup, connection attempts)
+  - Error handling and fallback behavior
+  - Concurrent peer discovery
+  - State transitions
+- **Test Results:** 15 integration tests, all passing
+- **Quality Gates:** All passing (cargo test, clippy, fmt)
+- **Phase 5 Status:** ✅ **COMPLETE** (123/123 SP, 100%)
+- **Components Delivered:**
+  - Privacy-enhanced Kademlia DHT (Sprints 5.1-5.2)
+  - DERP-style relay infrastructure (Sprints 5.3-5.4)
+  - NAT traversal with STUN/ICE (Sprint 5.4)
+  - Unified discovery manager (Sprint 5.5)
+
 **Phase 5 Sprint 5.4: Relay Infrastructure (2025-11-30):**
 - Implemented DERP-style relay infrastructure for NAT traversal
   - `RelayMessage` protocol with 9 message types (Register, SendPacket, RecvPacket, etc.)

README.md

@@ -38,16 +38,16 @@ WRAITH Protocol has completed Phases 1-4, delivering a fully functional core pro
 - **Documentation:** Comprehensive technical debt tracking (6 files in `to-dos/technical-debt/`)
 
 **Implementation Status:**
-- Core workspace: 8 crates (7 active + 1 XDP), ~21,000+ lines of Rust code
-- Test coverage: **607 passing tests** (197 wraith-core + 123 wraith-crypto + 24 vectors + 130 wraith-obfuscation unit + 54 wraith-transport + 16 wraith-files + 15 integration + 52 doctests)
+- Core workspace: 9 crates (8 active + 1 XDP), ~22,500+ lines of Rust code
+- Test coverage: **622 passing tests** (197 wraith-core + 123 wraith-crypto + 24 vectors + 130 wraith-obfuscation unit + 54 wraith-transport + 16 wraith-files + 15 wraith-discovery integration + 63 doctests)
   - wraith-core: 197 tests (frame parsing with validation hardening, session management, stream multiplexing, BBR congestion control with pacing, path MTU, connection migration)
   - wraith-crypto: 123 tests (Ed25519 signatures, X25519, Elligator2, XChaCha20-Poly1305 AEAD with key commitment, BLAKE3, Noise_XX, Double Ratchet, replay protection, constant-time ops)
   - wraith-transport: 54 tests (AF_XDP zero-copy sockets with batch processing, worker pools, UDP, MTU discovery, NUMA allocation)
   - wraith-obfuscation: 167 tests total (130 unit + 37 doctests: padding engine with 5 modes, timing obfuscation with 5 distributions, TLS 1.3 mimicry, WebSocket framing, DoH tunneling, adaptive profiles)
   - wraith-files: 16 tests total (12 unit + 4 doctests: io_uring async file I/O with registered buffers, chunking, BLAKE3 hashing)
+  - wraith-discovery: 15 integration tests (discovery manager lifecycle, peer connection flow, DHT/NAT/Relay integration)
   - Integration vectors: 24 tests (cryptographic correctness, full pipeline validation)
-  - Integration tests: 15 tests (session crypto, frame encryption, ratcheting)
-  - Doctests: 52 tests (API documentation examples across all crates)
+  - Doctests: 63 tests (API documentation examples across all crates)
 - Benchmarks: 28 criterion benchmarks (frame parsing/building, transport throughput/latency, MTU cache, worker pools, obfuscation operations)
 - Performance: 172M frames/sec parsing (~232 GiB/s theoretical throughput), 3.2 GB/s AEAD encryption, 8.5 GB/s BLAKE3 hashing
 - Documentation: 63+ files, 45,000+ lines, complete frame type specifications, comprehensive API docs
@@ -61,16 +61,17 @@ WRAITH Protocol has completed Phases 1-4, delivering a fully functional core pro
 - ✅ **Phase 3:** AF_XDP zero-copy networking, io_uring async I/O, UDP transport, worker thread pools, NUMA allocation, MTU discovery
 - ✅ **Phase 4 Part I:** AF_XDP batch processing (rx_batch/tx_batch), BBR pacing enforcement, io_uring registered buffers, frame validation hardening (reserved stream IDs, offset bounds, payload limits)
 - ✅ **Phase 4 Part II:** Complete traffic obfuscation layer - PaddingEngine (5 modes), TimingObfuscator (5 distributions), TLS 1.3 mimicry, WebSocket framing, DNS-over-HTTPS tunneling, adaptive threat-level profiles
+- ✅ **Phase 5:** Discovery & NAT Traversal - Privacy-enhanced Kademlia DHT with encrypted announcements, STUN/ICE NAT traversal with hole punching, DERP-style relay infrastructure, unified DiscoveryManager with end-to-end connection flow
 - ✅ **Advanced Features:** Path MTU Discovery, Connection Migration, Cover Traffic Generation, Buffer Pools, XDP packet filtering, 15 documented frame types
-- ✅ Comprehensive test suite (607 tests)
+- ✅ Comprehensive test suite (622 tests)
 - ✅ Performance benchmarks (28 criterion benchmarks)
 - ✅ Security documentation (SECURITY.md, TECH-DEBT.md)
 
-**Next: Phase 5 - Discovery & NAT Traversal (123 story points, 5-7 weeks)**
-- Privacy-enhanced DHT implementation
-- STUN-like NAT traversal
-- Relay infrastructure
-- Peer discovery mechanisms
+**Next: Phase 6 - Integration & End-to-End Testing**
+- Full protocol integration
+- Performance validation
+- Security hardening
+- Documentation finalization
 
 ## Features
 

crates/wraith-discovery/src/lib.rs

@@ -35,10 +35,15 @@
 #![warn(clippy::all)]
 
 pub mod dht;
+pub mod manager;
 pub mod nat;
 pub mod relay;
 
 // Re-export commonly used types
+pub use manager::{
+    ConnectionType, DiscoveryConfig, DiscoveryError, DiscoveryManager, DiscoveryState,
+    PeerConnection, RelayInfo,
+};
 pub use nat::{
     Candidate, CandidateType, HolePuncher, IceGatherer, NatDetector, NatError, NatType, PunchError,
     StunClient, StunError,