WASM bridge: web client now uses same crypto as CLI (full interop)

warzone-wasm crate:
- Compiles warzone-protocol to WebAssembly via wasm-pack
- Exposes WasmIdentity, WasmSession, decrypt_wire_message to JS
- Same X25519 + ChaCha20-Poly1305 + X3DH + Double Ratchet as CLI
- 344KB WASM binary (optimized with wasm-opt)

WireMessage moved to warzone-protocol:
- Shared type used by CLI client, WASM bridge, and TUI
- Guarantees identical bincode serialization across all clients

Web client rewritten:
- Loads WASM module on startup (/wasm/warzone_wasm.js)
- Identity: WasmIdentity generates same key types as CLI
- Registration: sends bincode PreKeyBundle (same format as CLI)
- Encrypt: WasmSession.encrypt/encrypt_key_exchange
- Decrypt: decrypt_wire_message (handles KeyExchange + Message)
- Sessions persisted in localStorage (base64 ratchet state)
- Groups: per-member WASM encryption (interop with CLI members)

Server routes:
- GET /wasm/warzone_wasm.js — serves WASM JS glue
- GET /wasm/warzone_wasm_bg.wasm — serves WASM binary
- Both embedded at compile time via include_str!/include_bytes!

Web ↔ CLI interop now works:
- Same key exchange (X3DH with X25519)
- Same ratchet (Double Ratchet with ChaCha20-Poly1305)
- Same wire format (bincode WireMessage)
- Web user can message CLI user and vice versa

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

warzone/crates/warzone-wasm/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+name = "warzone-wasm"
+version.workspace = true
+edition.workspace = true
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+warzone-protocol = { path = "../warzone-protocol" }
+wasm-bindgen = "0.2"
+serde = { workspace = true }
+serde_json = { workspace = true }
+js-sys = "0.3"
+web-sys = { version = "0.3", features = ["console"] }
+getrandom = { version = "0.2", features = ["js"] }
+base64.workspace = true
+hex.workspace = true
+bincode.workspace = true
+x25519-dalek.workspace = true
+uuid = { version = "1", features = ["v4", "serde", "js"] }
+
+[profile.release]
+opt-level = "s"
+lto = true