fix: a terminal resize reaches screens holding a text input

Non-key messages are forwarded to whichever text input a screen owns,
and that branch returns, so the resize never reached the handler that
records the new size. Every screen with a search field or a form —
Run workflow, Run commands, the name inputs — kept drawing for the
terminal it started in, while screens without one resized correctly.

A resize belongs to no single sub-model, so it is now taken before any
forwarding. The inputs are deliberately not told: their widths are
fixed on purpose, so a wide terminal does not stretch a name field
across the screen.

Author: Taka-S-dev

internal/tui/update.go

@@ -9,6 +9,16 @@ import (
 type runReadyMsg struct{}
 
 func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	// A resize is every screen's business, so it is handled before the
+	// forwarding below — which returns early and would otherwise leave
+	// the layout stale on any screen holding a text input.
+	if ws, ok := msg.(tea.WindowSizeMsg); ok {
+		m.width = ws.Width
+		m.height = ws.Height
+		m.updateStepsViewport()
+		return m, nil
+	}
+
 	// Always forward to spinner so TickMsg animates it.
 	{
 		s, c := m.spinner.Update(msg)
@@ -51,11 +61,6 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	}
 
 	switch msg := msg.(type) {
-	case tea.WindowSizeMsg:
-		m.width = msg.Width
-		m.height = msg.Height
-		m.updateStepsViewport()
-		return m, nil
 	case runReadyMsg:
 		if m.running != nil {
 			m.running.starting = false

internal/tui/update_test.go

@@ -0,0 +1,67 @@
+package tui
+
+import (
+	"testing"
+
+	"github.com/charmbracelet/bubbles/spinner"
+	"github.com/charmbracelet/bubbles/textinput"
+	tea "github.com/charmbracelet/bubbletea"
+
+	mdl "github.com/Taka-S-dev/baton/internal/model"
+)
+
+// TestUpdate_ResizeReachesEveryScreen guards the dispatch order: screens
+// holding a text input forward every non-key message to it and return,
+// so a resize arriving there used to be swallowed and the layout stayed
+// sized for the old terminal. Every screen must see it.
+func TestUpdate_ResizeReachesEveryScreen(t *testing.T) {
+	screens := []Screen{
+		ScreenMainMenu,
+		ScreenRunWorkflow,    // wfSearchTI
+		ScreenRunCommands,    // msSearchTI
+		ScreenCreateWorkflow, // msSearchTI
+		ScreenNameInput,      // nameInput
+		ScreenCommandForm,    // nameInput
+		ScreenVarForm,        // nameInput
+		ScreenSlotPick,
+		ScreenConfirmRun,
+		ScreenRunWorkflowSteps,
+	}
+	for _, sc := range screens {
+		m := Model{screen: sc, width: 80, height: 24}
+		m.spinner = spinner.New()
+		m.nameInput = textinput.New()
+		m.msSearchTI = textinput.New()
+		m.wfSearchTI = textinput.New()
+		m.workflows = []mdl.Workflow{{Name: "wf", Commands: []string{"a"}}}
+
+		nm, _ := m.Update(tea.WindowSizeMsg{Width: 120, Height: 40})
+		got := nm.(Model)
+		if got.width != 120 || got.height != 40 {
+			t.Errorf("screen %v: size = %dx%d, want 120x40 — the resize was swallowed",
+				sc, got.width, got.height)
+		}
+	}
+}
+
+// TestUpdate_ResizeResizesStepsPreview checks the steps viewport is
+// rebuilt for the new size rather than keeping the dimensions it was
+// given at startup.
+func TestUpdate_ResizeResizesStepsPreview(t *testing.T) {
+	m := Model{screen: ScreenRunWorkflow, width: 80, height: 24}
+	m.spinner = spinner.New()
+	m.wfSearchTI = textinput.New()
+	m.config = mdl.Config{Base: []mdl.Command{{Name: "a", Cmd: "echo hi"}}}
+	m.workflows = []mdl.Workflow{{Name: "wf", Commands: []string{"a"}}}
+	m.updateStepsViewport()
+	before := m.stepsVP.Width
+
+	nm, _ := m.Update(tea.WindowSizeMsg{Width: 140, Height: 50})
+	got := nm.(Model)
+	if got.stepsVP.Width == before {
+		t.Fatalf("steps preview width stayed %d after a resize to 140", before)
+	}
+	if got.stepsVP.Width != 140-4 {
+		t.Fatalf("steps preview width = %d, want the new terminal width less its frame", got.stepsVP.Width)
+	}
+}