v0.0.13: Sender Keys for efficient group encryption

Protocol (sender_keys.rs):
- SenderKey: symmetric key with chain ratchet (forward secrecy per chain)
- generate(), rotate(), encrypt(), decrypt()
- SenderKeyDistribution: share key via 1:1 encrypted channel
- SenderKeyMessage: encrypted group message (O(1) instead of O(N))
- Chain key ratchets forward on each message (HKDF)
- Generation counter for key rotation tracking
- 4 tests: basic, multi-message, rotation, old-key rejection

WireMessage:
- GroupSenderKey variant: encrypted group message
- SenderKeyDistribution variant: key sharing

Server: dedup handles new variants.
CLI TUI + recv: stub handlers for new message types.
23/23 protocol tests pass.

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

warzone/crates/warzone-server/src/routes/messages.rs

@@ -18,6 +18,10 @@ fn extract_message_id(data: &[u8]) -> Option<String> {
             WireMessage::FileHeader { id, .. } => Some(id),
             WireMessage::FileChunk { id, .. } => Some(id),
             WireMessage::Receipt { message_id, .. } => Some(message_id),
+            WireMessage::GroupSenderKey { id, .. } => Some(id),
+            WireMessage::SenderKeyDistribution { sender_fingerprint, group_name, .. } => {
+                Some(format!("skd:{}:{}", sender_fingerprint, group_name))
+            }
         }
     } else {
         None

warzone/crates/warzone-server/src/routes/ws.rs

@@ -30,6 +30,10 @@ fn extract_message_id(data: &[u8]) -> Option<String> {
             WireMessage::FileHeader { id, .. } => Some(id),
             WireMessage::FileChunk { id, .. } => Some(id),
             WireMessage::Receipt { message_id, .. } => Some(message_id),
+            WireMessage::GroupSenderKey { id, .. } => Some(id),
+            WireMessage::SenderKeyDistribution { sender_fingerprint, group_name, .. } => {
+                Some(format!("skd:{}:{}", sender_fingerprint, group_name))
+            }
         }
     } else {
         None