feat: mouse-wheel scrolls the view (editor/preview/picker)

@@ -38,6 +38,7 @@
 | Key | Action |
 | --- | --- |
 | type / arrows / `Enter` / `Backspace` / `Del` | edit and move (Up/Down move by visual line) |
+| mouse wheel | scroll the view (hold `Option`/`Shift` to select text while mouse mode is on) |
 | `Ctrl+U` / `Ctrl+K` | delete to start / end of line (map `Cmd+Delete`→`Ctrl+U` in your terminal) |
 | `Ctrl+S` | save (an unnamed buffer prompts for a name → inbox) |
 | `Ctrl+P` | toggle the Glamour read preview |

@@ -1,9 +1,10 @@
 ---
 id: TASK-003
 title: Wrapped-line vertical move can skip a row at a trailing-space boundary
-status: "\U0001F7E6 Backlog"
+status: "\U0001F3C1 Done"
 assignee: []
 created_date: '2026-06-28 18:38'
+updated_date: '2026-06-29 01:18'
 labels:
   - bug
 dependencies: []

@@ -126,6 +126,37 @@ 		a.setSize(msg.Width, msg.Height)
 		return a, nil
 	case tea.KeyMsg:
 		return a.handleKey(msg)
+	case tea.MouseMsg:
+		return a.handleMouse(msg)
+	}
+	return a, nil
+}
+
+// handleMouse scrolls the active view on wheel events without moving the cursor.
+func (a *App) handleMouse(msg tea.MouseMsg) (tea.Model, tea.Cmd) {
+	const step = 3
+	var delta int
+	switch msg.Button {
+	case tea.MouseButtonWheelUp:
+		delta = -step
+	case tea.MouseButtonWheelDown:
+		delta = step
+	default:
+		return a, nil
+	}
+	switch a.mode {
+	case ModePreview:
+		return a, a.preview.Update(msg) // the viewport handles wheel scrolling
+	case ModePicker:
+		key := tea.KeyMsg{Type: tea.KeyDown}
+		if delta < 0 {
+			key.Type = tea.KeyUp
+		}
+		for i := 0; i < step; i++ {
+			a.picker.Update(key)
+		}
+	default: // editor / save-as
+		a.editor.ScrollBy(delta)
 	}
 	return a, nil
 }

@@ -530,3 +530,19 @@ 	if sel := a.picker.Selected(); !strings.HasPrefix(sel, vault) {
 		t.Errorf("vault picker selected %q, want a file under the vault %q", sel, vault)
 	}
 }
+
+func TestMouseWheelScrollsEditorNotCursor(t *testing.T) {
+	a := newApp()
+	a.Update(tea.WindowSizeMsg{Width: 80, Height: 8})
+	for i := 0; i < 40; i++ {
+		a.editor.Lines = append(a.editor.Lines, "line")
+	}
+	a.editor.Cursor.Row, a.editor.Cursor.Col = 0, 0
+	a.Update(tea.MouseMsg{Button: tea.MouseButtonWheelDown})
+	if a.editor.Scroll == 0 {
+		t.Error("wheel down should scroll the editor viewport")
+	}
+	if a.editor.Cursor.Row != 0 || a.editor.Cursor.Col != 0 {
+		t.Errorf("wheel should not move the cursor; got %+v", a.editor.Cursor)
+	}
+}

@@ -84,6 +84,22 @@ 	e.setGoal()
 	e.followCursor()
 }
 
+// ScrollBy moves the viewport by delta visual rows (negative = up) without
+// moving the cursor, clamped so it never scrolls past the content.
+func (e *Editor) ScrollBy(delta int) {
+	max := len(e.buildVisual()) - e.Height
+	if max < 0 {
+		max = 0
+	}
+	e.Scroll += delta
+	if e.Scroll < 0 {
+		e.Scroll = 0
+	}
+	if e.Scroll > max {
+		e.Scroll = max
+	}
+}
+
 // KillToLineEnd deletes from the cursor to the end of the line (Ctrl+K).
 func (e *Editor) KillToLineEnd() {
 	rs := e.curLine()

@@ -342,3 +342,21 @@ 	if e.Cursor.Row != 1 {
 		t.Errorf("Cursor.Row = %d, want 1", e.Cursor.Row)
 	}
 }
+
+func TestScrollByClamps(t *testing.T) {
+	e := New()
+	for i := 0; i < 20; i++ {
+		e.Lines = append(e.Lines, "x")
+	}
+	e.SetSize(80, 5)
+	e.Cursor = Position{Row: 0, Col: 0}
+	e.ScrollBy(-5) // can't go below 0
+	if e.Scroll != 0 {
+		t.Errorf("Scroll = %d, want 0", e.Scroll)
+	}
+	e.ScrollBy(100) // clamps to max
+	max := len(e.buildVisual()) - e.Height
+	if e.Scroll != max {
+		t.Errorf("Scroll = %d, want %d (clamped)", e.Scroll, max)
+	}
+}

@@ -68,7 +68,7 @@ }
 
 // run drives the Bubbletea program in the alternate screen.
 func run(a *app.App) {
-	if _, err := tea.NewProgram(a, tea.WithAltScreen()).Run(); err != nil {
+	if _, err := tea.NewProgram(a, tea.WithAltScreen(), tea.WithMouseCellMotion()).Run(); err != nil {
 		fmt.Fprintln(os.Stderr, "glint:", err)
 		os.Exit(1)
 	}