TSS sheets store their file name

internal/styles/tss/tss.go

@@ -5,6 +5,7 @@ import "git.tebibyte.media/tomo/tomo/event"
 import "git.tebibyte.media/tomo/backend/style"
 
 type Sheet struct {
+	Path      string
 	Variables map[string] ValueList
 	Rules     []Rule
 	flat      bool
@@ -75,5 +76,6 @@ func LoadFile (name string) (*style.Style, event.Cookie, error) {
 
 	sheet, err := Parse(Lex(name, file))
 	if err != nil { return nil, nil, err }
+	sheet.Path = name
 	return BuildStyle(sheet)
 }