🐛 fix: apply final resize after debounce instead of dropping it

internal/sshserver/server.go

@@ -447,17 +447,36 @@ type termSize struct {
 	width   int
 	height  int
 	updated time.Time
+	timer   *time.Timer
 }
 
 func (t *termSize) set(w, h, maxDimension, maxCells int, force bool) {
+	width, height := clampTermSize(w, h, maxDimension, maxCells, terminalSizeQuantum)
+
 	t.mu.Lock()
-	if !force && time.Since(t.updated) < resizeDebounce {
-		t.mu.Unlock()
-		return
+	defer t.mu.Unlock()
+
+	if !force {
+		if remaining := resizeDebounce - time.Since(t.updated); remaining > 0 {
+			if t.timer != nil {
+				t.timer.Stop()
+			}
+			t.timer = time.AfterFunc(remaining, func() {
+				t.mu.Lock()
+				defer t.mu.Unlock()
+				t.width, t.height = width, height
+				t.updated = time.Now()
+			})
+			return
+		}
 	}
-	t.width, t.height = clampTermSize(w, h, maxDimension, maxCells, terminalSizeQuantum)
+
+	if t.timer != nil {
+		t.timer.Stop()
+		t.timer = nil
+	}
+	t.width, t.height = width, height
 	t.updated = time.Now()
-	t.mu.Unlock()
 }
 
 func (t *termSize) get() (int, int) {

internal/sshserver/server_test.go

@@ -3,6 +3,7 @@ package sshserver
 import (
 	"sync"
 	"testing"
+	"time"
 
 	"golang.org/x/crypto/ssh"
 )
@@ -102,6 +103,26 @@ func TestTermSizeDebouncesResize(t *testing.T) {
 	}
 }
 
+func TestTermSizeAppliesFinalResizeAfterDebounce(t *testing.T) {
+	size := &termSize{}
+	size.set(80, 24, 512, 500*512, true)
+
+	// Rapid burst of resize events, as happens during an interactive drag-resize.
+	size.set(100, 40, 512, 500*512, false)
+	size.set(150, 60, 512, 500*512, false)
+	size.set(200, 100, 512, 500*512, false)
+
+	if w, h := size.get(); w != 80 || h != 24 {
+		t.Fatalf("size changed before debounce elapsed: %dx%d", w, h)
+	}
+
+	time.Sleep(resizeDebounce + 50*time.Millisecond)
+
+	if w, h := size.get(); w != 200 || h != 100 {
+		t.Fatalf("final resize was not applied after debounce: got %dx%d, want 200x100", w, h)
+	}
+}
+
 func TestClampTermSize(t *testing.T) {
 	w, h := clampTermSize(1000, 500, 512, 65536, 4)
 	if w < 1 || h < 1 || w > 512 || h > 512 || w*h > 65536 {