feat: fix Cursor hook delivery and improve notify workflow

Route hook notifications through /dev/tty and client_tty so OSC reaches
Ghostty when Cursor captures stdout. Add afterAgentResponse hook, hook
logging, debounce, split test modes, and use directory name for titles.

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

internal/logx/log_test.go

@@ -0,0 +1,29 @@
+package logx
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestAppendAndTail(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("HOME", dir)
+
+	Append("hello %s", "world")
+	lines, err := Tail(10)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(lines) != 1 {
+		t.Fatalf("expected 1 line, got %d", len(lines))
+	}
+	if lines[0] == "" {
+		t.Fatal("empty line")
+	}
+
+	path := filepath.Join(dir, ".local", "state", "agent-notify", "hook.log")
+	if _, err := os.Stat(path); err != nil {
+		t.Fatalf("log file not created: %v", err)
+	}
+}