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/proto/proto.go

@@ -280,6 +280,8 @@ type IpcMessage struct {
 	BytesReceived  int64        `json:"bytes_received,omitempty"`
 	TotalBytes     int64        `json:"total_bytes,omitempty"`
 	// state_snapshot fields (existing shape preserved for backward compat)
+	MasterAlias    string        `json:"master_alias,omitempty"` // daemon's alias (available before any network join)
+	MasterID       string        `json:"master_id,omitempty"`    // daemon's master public key hex
 	LocalPeer      *PeerInfo     `json:"local_peer,omitempty"`
 	ConnectedPeers []PeerInfo    `json:"connected_peers,omitempty"`
 	Rooms          []string      `json:"rooms,omitempty"`