fix: insert CSI u handler into model.go + add tui tests

The previous commit defined parseCSIuBytes but failed to insert the
handler into Update(). Now properly inserted before the textinput
fallback. Add 10 test cases for parseCSIuBytes covering ctrl+alt+f/c/
m/p/h, ctrl+shift+c, alt+c, and invalid sequences.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/tui/model.go

@@ -240,6 +240,28 @@ func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		}
 	}
 
+
+		// Handle CSI u sequences that bubbletea does not parse into KeyMsg
+		if b, ok := msg.([]byte); ok {
+			if key, ok2 := parseCSIuBytes(b); ok2 {
+				keyStr := strings.ToLower(key)
+				if m.showModal {
+					last := rune(key[len(key)-1])
+					fake := tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{last}, Alt: strings.Contains(key, "alt+")}
+					if handled, _ := m.handleModalKey(fake); handled {
+						return m, nil
+					}
+				}
+				if keyStr == normalizeHotkeyPrefix(m.App.Cfg().HotkeyMod)+"+c" {
+					m.App.Close()
+					return m, tea.Quit
+				}
+				if handleLocalHotkey(m, keyStr) {
+					return m, nil
+				}
+			}
+		}
+
 	var cmd tea.Cmd
 	m.input, cmd = m.input.Update(msg)
 	return m, cmd

internal/tui/tui_test.go

@@ -0,0 +1,33 @@
+package tui
+
+import "testing"
+
+func TestParseCSIuBytes(t *testing.T) {
+	tests := []struct {
+		name string
+		seq  []byte
+		want string
+		ok   bool
+	}{
+		{name: "ctrl+alt+f", seq: []byte{0x1b, '[', '1', '0', '2', ';', '6', 'u'}, want: "ctrl+alt+f", ok: true},
+		{name: "ctrl+alt+c", seq: []byte{0x1b, '[', '9', '9', ';', '6', 'u'}, want: "ctrl+alt+c", ok: true},
+		{name: "ctrl+alt+m", seq: []byte{0x1b, '[', '1', '0', '9', ';', '6', 'u'}, want: "ctrl+alt+m", ok: true},
+		{name: "ctrl+alt+p", seq: []byte{0x1b, '[', '1', '1', '2', ';', '6', 'u'}, want: "ctrl+alt+p", ok: true},
+		{name: "ctrl+alt+h", seq: []byte{0x1b, '[', '1', '0', '4', ';', '6', 'u'}, want: "ctrl+alt+h", ok: true},
+		{name: "ctrl+shift+c", seq: []byte{0x1b, '[', '9', '9', ';', '5', 'u'}, want: "ctrl+shift+c", ok: true},
+		{name: "alt+c (no ctrl)", seq: []byte{0x1b, '[', '9', '9', ';', '2', 'u'}, want: "alt+c", ok: true},
+		{name: "plain c", seq: []byte{0x1b, '[', '9', '9', ';', '0', 'u'}, want: "c", ok: true},
+		{name: "not CSI u", seq: []byte{0x1b, '[', 'A'}, want: "", ok: false},
+		{name: "empty", seq: []byte{}, want: "", ok: false},
+		{name: "no escape", seq: []byte("hello"), want: "", ok: false},
+		{name: "ESC [ A (arrow up)", seq: []byte{0x1b, '[', 'A'}, want: "", ok: false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, ok := parseCSIuBytes(tt.seq)
+			if ok != tt.ok || got != tt.want {
+				t.Fatalf("parseCSIuBytes(%v): got=(%q,%v) want=(%q,%v)", tt.seq, got, ok, tt.want, tt.ok)
+			}
+		})
+	}
+}