Scaffold Rust workspace: warzone-protocol, server, client, mule

4 crates, all compile. 16/17 tests pass.

warzone-protocol (core crypto):
- Seed-based identity (Ed25519 + X25519 from 32-byte seed via HKDF)
- BIP39 mnemonic encode/decode (24 words)
- Fingerprint type (SHA-256 truncated, displayed as xxxx:xxxx:xxxx:xxxx)
- ChaCha20-Poly1305 AEAD encrypt/decrypt with random nonce
- HKDF-SHA256 key derivation
- Pre-key bundle generation with Ed25519 signatures
- X3DH key exchange (simplified, needs X25519 identity key in bundle)
- Double Ratchet: full implementation with DH ratchet, chain ratchet,
  out-of-order message handling via skipped keys cache
- Message format (WarzoneMessage envelope + RatchetHeader)
- Session type with ratchet state
- Storage trait definitions (PreKeyStore, SessionStore, MessageQueue)

warzone-server (axum):
- sled database (keys, messages, one-time pre-keys)
- Routes: /v1/health, /v1/keys/register, /v1/keys/{fp},
  /v1/messages/send, /v1/messages/poll/{fp}, /v1/messages/{id}/ack

warzone-client (CLI):
- `warzone init` — generate seed, show mnemonic, save to ~/.warzone/
- `warzone recover <words>` — restore from mnemonic
- `warzone info` — show fingerprint and keys
- Seed storage at ~/.warzone/identity.seed (600 perms)
- Stubs for send, recv, chat commands

warzone-mule: Phase 4 placeholder

Known issue: X3DH test fails (initiate/respond use different DH ops
due to missing X25519 identity key in bundle). Fix in next step.

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

warzone/target/debug/.fingerprint/sha2-b8a07d6eb3e82e75/invoked.timestamp

@@ -0,0 +1 @@
+This file has an mtime of when this was started.

warzone/target/debug/.fingerprint/sha2-b8a07d6eb3e82e75/lib-sha2

@@ -0,0 +1 @@
+b8380d380c1d6d0f

warzone/target/debug/.fingerprint/sha2-b8a07d6eb3e82e75/lib-sha2.json

@@ -0,0 +1 @@
+{"rustc":13850170861107434965,"features":"[\"default\", \"std\"]","declared_features":"[\"asm\", \"asm-aarch64\", \"compress\", \"default\", \"force-soft\", \"force-soft-compact\", \"loongarch64_asm\", \"oid\", \"sha2-asm\", \"std\"]","target":9593554856174113207,"profile":8276155916380437441,"path":3541895538589172545,"deps":[[7667230146095136825,"cfg_if",false,2728344822533571076],[17475753849556516473,"digest",false,15520245314284138113],[17620084158052398167,"cpufeatures",false,4346488927134455268]],"local":[{"CheckDepInfo":{"dep_info":"debug/.fingerprint/sha2-b8a07d6eb3e82e75/dep-lib-sha2","checksum":false}}],"rustflags":[],"config":2069994364910194474,"compile_kind":0}