Fix TUI startup and test script bugs

- TUI: replace per-call bufio.Scanner with a goroutine+channel reader
  (lineReader) so a single scanner lives for the connection lifetime;
  previous pattern silently dropped messages due to scanner read-ahead
- test-tui.sh / test-network.sh: add `return 0` to wait_port — when the
  port opens and the while condition becomes false, bash returned the
  condition's exit code (1) to the caller, tripping set -e immediately
- .gitignore: use /tui (root-only) instead of tui to avoid ignoring cmd/tui/

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

cmd/tui/main.go

@@ -42,11 +42,45 @@ const sideW = 22 // total width of each sidebar box (inner = sideW-2)
 
 // ── tea messages ──────────────────────────────────────────────────────────────
 
-type connectedMsg struct{ conn net.Conn }
+type connectedMsg struct {
+	conn   net.Conn
+	reader *lineReader
+}
 type ipcLineMsg struct{ line []byte }
 type connectErrMsg struct{ err error }
 type readErrMsg struct{ err error }
 
+// lineReader pumps a TCP connection through a channel so a single bufio.Scanner
+// is alive for the lifetime of the connection (avoids read-ahead data loss when
+// a new scanner is created on each call).
+type lineReader struct {
+	ch chan []byte
+}
+
+func newLineReader(conn net.Conn) *lineReader {
+	lr := &lineReader{ch: make(chan []byte, 64)}
+	go func() {
+		scanner := bufio.NewScanner(conn)
+		for scanner.Scan() {
+			b := make([]byte, len(scanner.Bytes()))
+			copy(b, scanner.Bytes())
+			lr.ch <- b
+		}
+		close(lr.ch)
+	}()
+	return lr
+}
+
+func (lr *lineReader) next() tea.Cmd {
+	return func() tea.Msg {
+		b, ok := <-lr.ch
+		if !ok {
+			return readErrMsg{fmt.Errorf("daemon closed connection")}
+		}
+		return ipcLineMsg{b}
+	}
+}
+
 // ── model ─────────────────────────────────────────────────────────────────────
 
 type entry struct {
@@ -62,8 +96,9 @@ type model struct {
 
 	width, height int
 
-	conn net.Conn
-	enc  *json.Encoder
+	conn   net.Conn
+	enc    *json.Encoder
+	reader *lineReader
 
 	localID    proto.PeerID
 	localAlias string
@@ -112,22 +147,7 @@ func connectCmd(port int) tea.Cmd {
 		if err != nil {
 			return connectErrMsg{err}
 		}
-		return connectedMsg{conn}
-	}
-}
-
-func listenCmd(conn net.Conn) tea.Cmd {
-	return func() tea.Msg {
-		scanner := bufio.NewScanner(conn)
-		if scanner.Scan() {
-			b := make([]byte, len(scanner.Bytes()))
-			copy(b, scanner.Bytes())
-			return ipcLineMsg{b}
-		}
-		if err := scanner.Err(); err != nil {
-			return readErrMsg{err}
-		}
-		return readErrMsg{fmt.Errorf("daemon closed connection")}
+		return connectedMsg{conn: conn, reader: newLineReader(conn)}
 	}
 }
 
@@ -156,11 +176,12 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	case connectedMsg:
 		m.conn = msg.conn
 		m.enc = json.NewEncoder(msg.conn)
+		m.reader = msg.reader
 		m.status = "joining " + m.networkName + "…"
 		cmds = append(cmds,
 			sendIPC(m.enc, proto.IpcMessage{Type: proto.CmdJoinNetwork, NetworkName: m.networkName}),
 			sendIPC(m.enc, proto.IpcMessage{Type: proto.CmdGetState}),
-			listenCmd(m.conn),
+			m.reader.next(),
 		)
 
 	case ipcLineMsg:
@@ -168,7 +189,7 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if json.Unmarshal(msg.line, &evt) == nil {
 			m = m.applyEvent(evt)
 		}
-		cmds = append(cmds, listenCmd(m.conn))
+		cmds = append(cmds, m.reader.next())
 
 	case readErrMsg:
 		m.errMsg = "IPC disconnected: " + msg.err.Error()