fix: SFTP auto-refresh + filter mode + delete refresh

- Clear dirCache before refresh after transfer/delete/mkdir
- Cache was stale: old entries returned instead of fresh data
- Filter mode: allow commands (c,d,n,r) and nav (↑↓,Tab) to pass through
- Filter mode no longer blocks transfer/delete/mkdir/pane-switch
- Delete: clear cache + program.Send() for re-render
- Mkdir: clear cache + program.Send() for re-render

pkg/tui/sftp_browser_tab.go

@@ -293,6 +293,10 @@ func (t *SFTPBrowserTab) Update(msg tea.Msg) (Tab, tea.Cmd) {
 					p.filter = p.filter[:len(p.filter)-1]
 				}
 				return t, nil
+			case "tab", "up", "k", "down", "j":
+				// Allow navigation and pane switch in filter mode
+			case "c", "d", "n", "r":
+				// Allow commands in filter mode
 			default:
 				if len(msg.Runes) == 1 {
 					p.filter += string(msg.Runes[0])
@@ -496,7 +500,15 @@ func (t *SFTPBrowserTab) copyFile(srcType, dstType paneType, srcPath, dstPath, n
 	t.transferring = false
 	t.mu.Unlock()
 
-	// Auto-refresh destination pane
+	// Auto-refresh destination pane (clear cache first)
+	t.mu.Lock()
+	if dstType == paneRemote {
+		delete(t.right.dirCache, t.right.cwd)
+	} else {
+		delete(t.left.dirCache, t.left.cwd)
+	}
+	t.mu.Unlock()
+
 	if dstType == paneRemote {
 		t.refreshRemote()
 	} else {
@@ -606,10 +618,24 @@ func (t *SFTPBrowserTab) deleteItem(fullPath string, isDir bool, isRemote bool)
 	t.transferMsg = ""
 	t.mu.Unlock()
 
+	// Clear cache and refresh
+	t.mu.Lock()
 	if isRemote {
-		go t.refreshRemote()
+		delete(t.right.dirCache, t.right.cwd)
 	} else {
-		go t.refreshLocal()
+		delete(t.left.dirCache, t.left.cwd)
+	}
+	t.mu.Unlock()
+
+	if isRemote {
+		t.refreshRemote()
+	} else {
+		t.refreshLocal()
+	}
+
+	// Trigger re-render
+	if t.program != nil {
+		t.program.Send(sftpRefreshMsg{})
 	}
 }
 
@@ -630,7 +656,17 @@ func (t *SFTPBrowserTab) mkdirRemote() {
 		t.mu.Unlock()
 		return
 	}
+
+	// Clear cache and refresh
+	t.mu.Lock()
+	delete(t.right.dirCache, cwd)
+	t.mu.Unlock()
 	t.refreshRemote()
+
+	// Trigger re-render
+	if t.program != nil {
+		t.program.Send(sftpRefreshMsg{})
+	}
 }
 
 func (t *SFTPBrowserTab) View() string {