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/resume.go

@@ -165,7 +165,7 @@ func runResume(cmd *cobra.Command, args []string) error {
 	// Clear parked work state
 	if err := clearParkedWork(cloneRoot, agentID); err != nil {
 		// Non-fatal
-		fmt.Printf("%s Warning: could not clear parked state: %v\n", style.Dim.Render("⚠"), err)
+		style.PrintWarning("could not clear parked state: %v", err)
 	}
 
 	fmt.Printf("\n%s Ready to continue!\n", style.Bold.Render("✓"))