feat(waiter): Bubble Tea TUI modernization

Replace the line-based REPL with a full-screen Bubble Tea TUI in
interactive mode (non-TTY still falls back to the line editor).

Layout (deveco-code inspired, no emoji):
  - Top status bar: HomeAgent brand + connection dot + mode + addr
  - Scrollable chat viewport with role-based rendering:
      You (purple)   user messages
      小宅 (orange)  agent responses
      · reasoning    dim gray italic, streaming-merged
      [ok]/[fail]    tool calls with status + truncated result
      [sys]          builtin command output
      [err]          errors
  - Rounded-border input box with placeholder
  - Bottom status bar: spinner while busy / hints + connection state

Key design points:
  - reader generation counter prevents stale errors from the old
    reader being mistaken for the new one after reconnect
  - handleSubmit always returns waitServer when reader is alive,
    so server responses to builtin commands like /status are received
  - History stored as *History (was copying sync.Mutex by value)
  - Chinese CJK wide-char aware word wrap with hanging indent
  - /clear /exit /quit handled in TUI; other /cmds still go through
    handleBuiltin with output captured to message area

Verified via tmux PTY: /help, /status, /clear, real chat with LLM
(reasoning -> tool_call -> response chain all render correctly).

cmd/waiter/builtin.go

@@ -1,9 +1,9 @@
 package main
 
 import (
-	"io"
 	"encoding/json"
 	"fmt"
+	"io"
 	"strings"
 )
 

cmd/waiter/history.go

@@ -13,8 +13,8 @@ type History struct {
 	mu    sync.Mutex
 }
 
-func newHistory(path string, max int) History {
-	return History{path: path, max: max}
+func newHistory(path string, max int) *History {
+	return &History{path: path, max: max}
 }
 
 func (h *History) load() {

cmd/waiter/main.go

@@ -239,11 +239,11 @@ func runCapTest(capName, args string) {
 }
 
 // runLineMode 传统行式 REPL（非 TTY 回退 / TUI 启动失败时使用）。
-func runLineMode(state *State, cfg *Config, history History) {
+func runLineMode(state *State, cfg *Config, history *History) {
 	sigCh := make(chan os.Signal, 1)
 	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM)
 
-	line := newLineEditor(&history)
+	line := newLineEditor(history)
 
 	restore, err := setRawMode(0)
 	if err != nil {

cmd/waiter/tui.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"context"
 	"fmt"
 	"strings"
 	"time"
@@ -80,7 +79,7 @@ type serverLineMsg struct{ line string }
 
 type readerErrMsg struct {
 	err error
-	gen int // reader 世代号：旧 reader 迟到的错误会被忽略
+	gen int
 }
 
 type reconnectDoneMsg struct{ ok bool }
@@ -109,14 +108,14 @@ type tuiModel struct {
 	historyDraft string
 
 	lines       chan string
-	errs        chan error
+	errs        chan readerErrMsg
 	readerGen   int // 当前 reader 世代；重启时递增
 	readerAlive bool
 
 	reconnecting bool
 }
 
-func newTuiModel(state *State, cfg *Config, history History, lines chan string, errs chan error) tuiModel {
+func newTuiModel(state *State, cfg *Config, history *History, lines chan string, errs chan readerErrMsg) tuiModel {
 	ti := textarea.New()
 	ti.Placeholder = "输入消息，/help 查看命令"
 	ti.Prompt = ""
@@ -130,7 +129,7 @@ func newTuiModel(state *State, cfg *Config, history History, lines chan string,
 		cfg:         cfg,
 		input:       ti,
 		vp:          viewport.New(80, 20),
-		history:     &history,
+		history:     history,
 		historyIdx:  -1,
 		lines:       lines,
 		errs:        errs,
@@ -143,13 +142,13 @@ func (m tuiModel) Init() tea.Cmd {
 }
 
 // waitServer 阻塞等待下一行服务器输出或读错误。
-func waitServer(lines chan string, errs chan error) tea.Cmd {
+func waitServer(lines chan string, errs chan readerErrMsg) tea.Cmd {
 	return func() tea.Msg {
 		select {
 		case l := <-lines:
 			return serverLineMsg{l}
 		case e := <-errs:
-			return readerErrMsg{e}
+			return e
 		}
 	}
 }
@@ -158,6 +157,14 @@ func spinTick() tea.Cmd {
 	return tea.Tick(90*time.Millisecond, func(time.Time) tea.Msg { return spinnerTickMsg{} })
 }
 
+// spinCmd busy 时启动 spinner tick 循环。
+func (m tuiModel) spinCmd() tea.Cmd {
+	if !m.busy {
+		return nil
+	}
+	return spinTick()
+}
+
 // reconnectCmd 后台重连（State 自带锁，goroutine 安全）。
 func (m tuiModel) reconnectCmd() tea.Cmd {
 	return func() tea.Msg {
@@ -197,7 +204,6 @@ func (m *tuiModel) readPump(gen int) {
 		}
 	}
 }
-}
 
 // ---------------------------------------------------------------------------
 // Update
@@ -332,6 +338,10 @@ func (m tuiModel) handleSubmit() (tea.Model, tea.Cmd) {
 				m.reconnecting = true
 				return m, m.reconnectCmd()
 			}
+			// 即使内置命令也可能触发服务器回复（如 /status），所以继续保持监听
+			if m.readerAlive {
+				return m, waitServer(m.lines, m.errs)
+			}
 			return m, nil
 		}
 	}
@@ -348,7 +358,10 @@ func (m tuiModel) handleSubmit() (tea.Model, tea.Cmd) {
 		m.reconnecting = true
 		return m, m.reconnectCmd()
 	}
-	return m, nil
+	if m.readerAlive {
+		return m, tea.Batch(waitServer(m.lines, m.errs), m.spinCmd())
+	}
+	return m, m.spinCmd()
 }
 
 func (m *tuiModel) handleServerLine(line string) {
@@ -622,7 +635,7 @@ func (m tuiModel) View() string {
 func (m tuiModel) statusLine() string {
 	var leftSeg string
 	if m.busy {
-		leftSeg = styleTitle.Render(spinnerFrames[m.spinnerIdx%len(spinnerFrames)]+" thinking...")
+		leftSeg = styleTitle.Render(spinnerFrames[m.spinnerIdx%len(spinnerFrames)] + " thinking...")
 	} else {
 		leftSeg = styleDim.Render("enter 发送 · PgUp/PgDn 翻页 · ctrl+c 退出")
 	}
@@ -666,8 +679,8 @@ func maxInt(a, b int) int {
 // ---------------------------------------------------------------------------
 
 // runTUI 启动 Bubble Tea 全屏界面。
-func runTUI(state *State, cfg *Config, history History) error {
-	m := newTuiModel(state, cfg, history, make(chan string, 128), make(chan error, 8))
+func runTUI(state *State, cfg *Config, history *History) error {
+	m := newTuiModel(state, cfg, history, make(chan string, 128), make(chan readerErrMsg, 8))
 	m.readerAlive = true
 	go m.readPump(m.readerGen) // 初始读循环