feat: implement agent-notify CLI with hooks and tmux passthrough

Add OSC 777 notification sender, Cursor/Claude hook adapters,
config/install commands, and README for Ghostty + tmux setup.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/notify/osc.go

@@ -0,0 +1,16 @@
+package notify
+
+import "strings"
+
+func BuildSequence(protocol, title, body string) string {
+	switch protocol {
+	case "osc9":
+		return "\033]9;" + escapeOSCField(body) + "\007"
+	default:
+		return "\033]777;notify;" + escapeOSCField(title) + ";" + escapeOSCField(body) + "\007"
+	}
+}
+
+func escapeOSCField(s string) string {
+	return strings.ReplaceAll(s, ";", "\\;")
+}

internal/notify/osc_test.go

@@ -0,0 +1,26 @@
+package notify
+
+import "testing"
+
+func TestBuildOSC777(t *testing.T) {
+	seq := BuildSequence("osc777", "Claude — proj", "等待输入")
+	want := "\033]777;notify;Claude — proj;等待输入\007"
+	if seq != want {
+		t.Fatalf("got %q want %q", seq, want)
+	}
+}
+
+func TestBuildOSC9(t *testing.T) {
+	seq := BuildSequence("osc9", "ignored", "等待输入")
+	want := "\033]9;等待输入\007"
+	if seq != want {
+		t.Fatalf("got %q want %q", seq, want)
+	}
+}
+
+func TestSemicolonInTitleEscaped(t *testing.T) {
+	seq := BuildSequence("osc777", "a;b", "body")
+	if seq != "\033]777;notify;a\\;b;body\007" {
+		t.Fatalf("unexpected escape: %q", seq)
+	}
+}

internal/notify/send.go

@@ -0,0 +1,71 @@
+package notify
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/longbin/agent-notify/internal/tmux"
+)
+
+type SendOptions struct {
+	Protocol  string
+	Title     string
+	Body      string
+	Writer    io.Writer
+	InTmux    bool
+	Layers    int
+	ClientTTY string
+}
+
+func Send(opts SendOptions) error {
+	seq := BuildSequence(opts.Protocol, opts.Title, opts.Body)
+	w := opts.Writer
+	if w == nil {
+		w = os.Stdout
+	}
+
+	if opts.InTmux && opts.ClientTTY != "" {
+		f, err := os.OpenFile(opts.ClientTTY, os.O_WRONLY, 0)
+		if err == nil {
+			defer f.Close()
+			_, err = io.WriteString(f, seq)
+			return err
+		}
+	}
+
+	out := seq
+	if opts.InTmux {
+		layers := opts.Layers
+		if layers <= 0 {
+			layers = 1
+		}
+		out = tmux.WrapPassthroughLayers(seq, layers)
+	}
+	_, err := io.WriteString(w, out)
+	return err
+}
+
+func SendAuto(protocol, title, body string) error {
+	inTmux := tmux.InTmux()
+	clientTTY, _ := tmux.ClientTTY()
+	layers := 0
+	if inTmux {
+		layers = 1
+	}
+	return Send(SendOptions{
+		Protocol:  protocol,
+		Title:     title,
+		Body:      body,
+		InTmux:    inTmux,
+		Layers:    layers,
+		ClientTTY: clientTTY,
+	})
+}
+
+func TestNotification(title, body string) error {
+	if err := SendAuto("osc777", title, body); err != nil {
+		return fmt.Errorf("send test notification: %w", err)
+	}
+	return nil
+}

internal/notify/send_test.go

@@ -0,0 +1,42 @@
+package notify
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestSendDirect(t *testing.T) {
+	var buf bytes.Buffer
+	err := Send(SendOptions{
+		Protocol: "osc777",
+		Title:    "Cursor — app",
+		Body:     "等待输入",
+		Writer:   &buf,
+		InTmux:   false,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Contains(buf.Bytes(), []byte("777;notify")) {
+		t.Fatalf("missing osc777: %q", buf.String())
+	}
+}
+
+func TestSendTmuxUsesPassthroughWhenNoTTY(t *testing.T) {
+	var buf bytes.Buffer
+	err := Send(SendOptions{
+		Protocol:  "osc777",
+		Title:     "t",
+		Body:      "b",
+		Writer:    &buf,
+		InTmux:    true,
+		Layers:    1,
+		ClientTTY: "",
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.HasPrefix(buf.Bytes(), []byte("\033Ptmux;")) {
+		t.Fatalf("expected passthrough prefix, got %q", buf.String())
+	}
+}