Standardize warning output to use style.PrintWarning (gt-g6kor)

- Add PrintWarning helper in internal/style/style.go
- Update 35 warning message outputs across 16 files to use consistent format
- All warnings now display as "⚠ Warning: <message>" in yellow/bold

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/cmd/handoff.go

@@ -148,7 +148,7 @@ func runHandoff(cmd *cobra.Command, args []string) error {
 	// If subject/message provided, send handoff mail to self first
 	if handoffSubject != "" || handoffMessage != "" {
 		if err := sendHandoffMail(handoffSubject, handoffMessage); err != nil {
-			fmt.Printf("%s Warning: could not send handoff mail: %v\n", style.Dim.Render("⚠"), err)
+			style.PrintWarning("could not send handoff mail: %v", err)
 			// Continue anyway - the respawn is more important
 		} else {
 			fmt.Printf("%s Sent handoff mail\n", style.Bold.Render("📬"))
@@ -172,7 +172,7 @@ func runHandoff(cmd *cobra.Command, args []string) error {
 	// Clear scrollback history before respawn (resets copy-mode from [0/N] to [0/0])
 	if err := t.ClearHistory(pane); err != nil {
 		// Non-fatal - continue with respawn even if clear fails
-		fmt.Printf("%s Warning: could not clear history: %v\n", style.Dim.Render("⚠"), err)
+		style.PrintWarning("could not clear history: %v", err)
 	}
 
 	// Use exec to respawn the pane - this kills us and restarts
@@ -458,7 +458,7 @@ func handoffRemoteSession(t *tmux.Tmux, targetSession, restartCmd string) error
 	// Clear scrollback history before respawn (resets copy-mode from [0/N] to [0/0])
 	if err := t.ClearHistory(targetPane); err != nil {
 		// Non-fatal - continue with respawn even if clear fails
-		fmt.Printf("%s Warning: could not clear history: %v\n", style.Dim.Render("⚠"), err)
+		style.PrintWarning("could not clear history: %v", err)
 	}
 
 	// Respawn the remote session's pane