v0.0.6: Delivery receipts (sent/delivered/read)

Protocol:
- WireMessage::Receipt { sender_fingerprint, message_id, receipt_type }
- ReceiptType enum: Delivered, Read
- id field added to KeyExchange and Message variants
- Receipts are plaintext (not encrypted) — contain only ID + type

Web client:
- Auto-sends Delivered receipt on successful decrypt
- Tracks sent message IDs with receipt status
- Displays: ✓ (sent, gray), ✓✓ (delivered, white), ✓✓ (read, blue)
- Receipt indicators update live via DOM reference

CLI TUI:
- Auto-sends Delivered receipt back to sender on decrypt
- Tracks receipt status per message ID
- Displays receipt indicators after sent messages

WASM:
- create_receipt() function for web client
- encrypt_with_id/encrypt_key_exchange_with_id for tracking
- decrypt_wire_message handles Receipt variant

17/17 protocol tests pass. Zero warnings.

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

warzone/crates/warzone-protocol/src/message.rs

@@ -34,12 +34,20 @@ pub enum MessageContent {
     Receipt { message_id: MessageId },
 }
 
+/// Receipt type: delivered (received + decrypted) or read (user viewed).
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
+pub enum ReceiptType {
+    Delivered,
+    Read,
+}
+
 /// Wire message format for transport between clients.
 /// Used by both CLI and WASM — MUST be identical for interop.
 #[derive(Clone, Serialize, Deserialize)]
 pub enum WireMessage {
     /// First message to a peer: X3DH key exchange + first ratchet message.
     KeyExchange {
+        id: String,
         sender_fingerprint: String,
         sender_identity_encryption_key: [u8; 32],
         ephemeral_public: [u8; 32],
@@ -48,7 +56,14 @@ pub enum WireMessage {
     },
     /// Subsequent messages: ratchet-encrypted.
     Message {
+        id: String,
         sender_fingerprint: String,
         ratchet_message: crate::ratchet::RatchetMessage,
     },
+    /// Delivery / read receipt (plaintext, not encrypted).
+    Receipt {
+        sender_fingerprint: String,
+        message_id: String,
+        receipt_type: ReceiptType,
+    },
 }