(new): rich message support

(fix): runtime reliability
(tests): regression coverage
(doc): v1.1 release notes

l10n.go

@@ -1,6 +1,9 @@
 package laniakea
 
-import "sync"
+import (
+	"maps"
+	"sync"
+)
 
 // DictEntry maps language codes to translated strings.
 type DictEntry map[string]string
@@ -64,8 +67,6 @@ func cloneDictEntry(src DictEntry) DictEntry {
 		return nil
 	}
 	cloned := make(DictEntry, len(src))
-	for lang, text := range src {
-		cloned[lang] = text
-	}
+	maps.Copy(cloned, src)
 	return cloned
 }