feat: WarzonePhone lossy VoIP protocol — Phase 1 complete

Rust workspace with 7 crates implementing a custom VoIP protocol
designed for extremely lossy connections (5-70% loss, 100-500kbps,
300-800ms RTT). 89 tests passing across all crates.

Crates:
- wzp-proto: Wire format, traits, adaptive quality controller, jitter buffer, session FSM
- wzp-codec: Opus encoder/decoder (audiopus), Codec2 stubs, adaptive switching, resampling
- wzp-fec: RaptorQ fountain codes, interleaving, block management (proven 30-70% loss recovery)
- wzp-crypto: X25519+ChaCha20-Poly1305, Warzone identity compatible, anti-replay, rekeying
- wzp-transport: QUIC via quinn with DATAGRAM frames, path monitoring, signaling streams
- wzp-relay: Integration stub (Phase 2)
- wzp-client: Integration stub (Phase 2)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/wzp-proto/src/lib.rs

@@ -0,0 +1,29 @@
+//! WarzonePhone Protocol — shared types, traits, and core logic.
+//!
+//! This crate defines the contracts between all other wzp-* crates.
+//! It contains:
+//! - Wire format types (MediaHeader, MediaPacket, SignalMessage)
+//! - Codec, FEC, crypto, and transport trait definitions
+//! - Adaptive quality controller
+//! - Jitter buffer
+//! - Session state machine
+//!
+//! Compatible with the Warzone messenger identity model:
+//! - Identity = 32-byte seed → HKDF → Ed25519 (signing) + X25519 (encryption)
+//! - Fingerprint = SHA-256(Ed25519 pub)[:16]
+
+pub mod codec_id;
+pub mod error;
+pub mod jitter;
+pub mod packet;
+pub mod quality;
+pub mod session;
+pub mod traits;
+
+// Re-export key types at crate root for convenience.
+pub use codec_id::{CodecId, QualityProfile};
+pub use error::*;
+pub use packet::{HangupReason, MediaHeader, MediaPacket, QualityReport, SignalMessage};
+pub use quality::{AdaptiveQualityController, Tier};
+pub use session::{Session, SessionEvent, SessionState};
+pub use traits::*;