✨ Add support for mixed-level nested keys with dot/blank handling

- Handle @parent:child and @parent🧒grandchild coexistence
- Use '.' key for parent values when nested children exist
- Add comprehensive test cases for double-nested scenarios
- Support both '.' and '' as special keys for parent values

models/metas.go

@@ -42,6 +42,7 @@ func (ms Metas) Map() map[string]any {
 }
 
 func parseNestedFields(f map[string]any) {
+	todelete := make([]string, 0, len(f))
 	for k, v := range f {
 		if strings.Contains(k, ":") {
 			idx := strings.Index(k, ":")
@@ -50,14 +51,28 @@ func parseNestedFields(f map[string]any) {
 
 			nest, ok := f[top].(map[string]any)
 			if !ok {
-				nest = map[string]any{}
+				curr := f[top]
+				if curr == nil {
+					nest = map[string]any{}
+				} else {
+					nest = map[string]any{".": curr}
+				}
+			}
+
+			curr, ok := nest[bottom].(map[string]any)
+			if ok {
+				curr["."] = v
+			} else {
+				nest[bottom] = v
 			}
-			nest[bottom] = v
 			parseNestedFields(nest)
 			f[top] = nest
-			delete(f, k)
+			todelete = append(todelete, k)
 		}
 	}
+	for _, k := range todelete {
+		delete(f, k)
+	}
 }
 
 // Implements json.Marshaler