chore: initial commit for v0.0.1

DChain single-node blockchain + React Native messenger client.

Core:
- PBFT consensus with multi-sig validator admission + equivocation slashing
- BadgerDB + schema migration scaffold (CurrentSchemaVersion=0)
- libp2p gossipsub (tx/v1, blocks/v1, relay/v1, version/v1)
- Native Go contracts (username_registry) alongside WASM (wazero)
- WebSocket gateway with topic-based fanout + Ed25519-nonce auth
- Relay mailbox with NaCl envelope encryption (X25519 + Ed25519)
- Prometheus /metrics, per-IP rate limit, body-size cap

Deployment:
- Single-node compose (deploy/single/) with Caddy TLS + optional Prometheus
- 3-node dev compose (docker-compose.yml) with mocked internet topology
- 3-validator prod compose (deploy/prod/) for federation
- Auto-update from Gitea via /api/update-check + systemd timer
- Build-time version injection (ldflags → node --version)
- UI / Swagger toggle flags (DCHAIN_DISABLE_UI, DCHAIN_DISABLE_SWAGGER)

Client (client-app/):
- Expo / React Native / NativeWind
- E2E NaCl encryption, typing indicator, contact requests
- Auto-discovery of canonical contracts, chain_id aware, WS reconnect on node switch

Documentation:
- README.md, CHANGELOG.md, CONTEXT.md
- deploy/single/README.md with 6 operator scenarios
- deploy/UPDATE_STRATEGY.md with 4-layer forward-compat design
- docs/contracts/*.md per contract

client-app/lib/types.ts

@@ -0,0 +1,86 @@
+// ─── Key material ────────────────────────────────────────────────────────────
+
+export interface KeyFile {
+  pub_key:      string;  // hex Ed25519 public key  (32 bytes)
+  priv_key:     string;  // hex Ed25519 private key (64 bytes)
+  x25519_pub:   string;  // hex X25519 public key   (32 bytes)
+  x25519_priv:  string;  // hex X25519 private key  (32 bytes)
+}
+
+// ─── Contact ─────────────────────────────────────────────────────────────────
+
+export interface Contact {
+  address:    string;  // Ed25519 pubkey hex — blockchain address
+  x25519Pub:  string;  // X25519 pubkey hex  — encryption key
+  username?:  string;  // @name from registry contract
+  alias?:     string;  // local nickname
+  addedAt:    number;  // unix ms
+}
+
+// ─── Messages ─────────────────────────────────────────────────────────────────
+
+export interface Envelope {
+  sender_pub:    string;  // X25519 hex
+  recipient_pub: string;  // X25519 hex
+  nonce:         string;  // hex 24 bytes
+  ciphertext:    string;  // hex NaCl box
+  timestamp:     number;  // unix seconds
+}
+
+export interface Message {
+  id:        string;
+  from:      string;   // X25519 pubkey of sender
+  text:      string;
+  timestamp: number;
+  mine:      boolean;
+}
+
+// ─── Chat ────────────────────────────────────────────────────────────────────
+
+export interface Chat {
+  contactAddress: string;  // Ed25519 pubkey hex
+  contactX25519:  string;  // X25519 pubkey hex
+  username?:      string;
+  alias?:         string;
+  lastMessage?:   string;
+  lastTime?:      number;
+  unread:         number;
+}
+
+// ─── Contact request ─────────────────────────────────────────────────────────
+
+export interface ContactRequest {
+  from:       string;   // Ed25519 pubkey hex
+  x25519Pub:  string;   // X25519 pubkey hex; empty until fetched from identity
+  username?:  string;
+  intro:      string;   // plaintext intro (stored on-chain)
+  timestamp:  number;
+  txHash:     string;
+}
+
+// ─── Transaction ─────────────────────────────────────────────────────────────
+
+export interface TxRecord {
+  hash:      string;
+  type:      string;
+  from:      string;
+  to?:       string;
+  amount?:   number;
+  fee:       number;
+  timestamp: number;
+  status:    'confirmed' | 'pending';
+}
+
+// ─── Node info ───────────────────────────────────────────────────────────────
+
+export interface NetStats {
+  total_blocks:   number;
+  total_txs:      number;
+  peer_count:     number;
+  chain_id:       string;
+}
+
+export interface NodeSettings {
+  nodeUrl:    string;
+  contractId: string;  // username_registry contract
+}