Fix web UI messaging, alias resolution, and onboarding

Messaging:
- Append \n to WS IPC sends so bufio.Scanner fires (messages from web
  were silently dropped — the line scanner never saw a newline)
- Handle session_ready in web store to update peer aliases after hello

Alias resolution:
- Seed AddPeer alias from SQLite cache so returning peers resolve
  immediately, before hello exchange completes
- Remove stale SavePeer call from AddPeer (was writing placeholder IDs)
- Add PeerAlias() point-lookup to store

Onboarding redesign:
- Three-state UI: disconnected (daemon instructions), connecting,
  connected-no-network (join form)
- Read ?n= / ?network= / ?anchor= / ?invite=waste:... URL params to
  pre-fill the join form for invite links
- Show daemon alias + peer ID before any network is joined
  (master_alias + master_id now included in state_snapshot)
- Identity backup: export (passphrase-protected yaw-key-backup-1 JSON,
  download button) and restore (paste + passphrase verify)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/ipc/ipc.go

@@ -345,9 +345,12 @@ func handleClient(conn net.Conn, mgr *netmgr.Manager) {
 func stateSnapshot(mgr *netmgr.Manager) proto.IpcMessage {
 	all := mgr.All()
 
+	master := mgr.MasterIdentity()
 	msg := proto.IpcMessage{
-		Type:  proto.EvtStateSnapshot,
-		Rooms: []string{"general"},
+		Type:        proto.EvtStateSnapshot,
+		Rooms:       []string{"general"},
+		MasterAlias: master.Alias,
+		MasterID:    string(master.PeerID()),
 	}
 
 	var netInfos []proto.NetworkInfo