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/Cargo.toml

@@ -9,7 +9,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.0.5"
+version = "0.0.6"
 edition = "2021"
 license = "MIT"
 rust-version = "1.75"