fix: log diagnostic when Update type assertion fails

Add log.Printf in the !ok branch so unexpected return types from
message handlers are logged instead of silently swallowed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mariusvniekerk

cmd/roborev/tui/tui.go

@@ -2,6 +2,7 @@ package tui
 
 import (
 	"errors"
+	"log"
 	"net"
 	"net/http"
 	neturl "net/url"
@@ -656,6 +657,7 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	// click and wheel support.
 	updated, ok := newM.(model)
 	if !ok {
+		log.Printf("tui: Update returned unexpected type %T; skipping mouse toggle", newM)
 		return newM, cmd
 	}
 	newView := updated.currentView