Fix meta.json validation errors by flattening nested pages structure

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

content/docs/concepts/meta.cn.json

@@ -5,22 +5,17 @@
     "manifesto",
     "core-values",
     "architecture",
-    {
-      "title": "协议命名空间",
-      "pages": [
-        "protocol-data",
-        "protocol-driver",
-        "protocol-permission",
-        "protocol-ui",
-        "protocol-system",
-        "protocol-auth",
-        "protocol-kernel",
-        "protocol-hub",
-        "protocol-ai",
-        "protocol-api",
-        "protocol-automation"
-      ]
-    },
+    "protocol-data",
+    "protocol-driver",
+    "protocol-permission",
+    "protocol-ui",
+    "protocol-system",
+    "protocol-auth",
+    "protocol-kernel",
+    "protocol-hub",
+    "protocol-ai",
+    "protocol-api",
+    "protocol-automation",
     "plugin-architecture",
     "security_architecture",
     "enterprise-patterns",

content/docs/concepts/meta.json

@@ -5,22 +5,17 @@
     "manifesto",
     "core-values",
     "architecture",
-    {
-      "title": "Protocol Namespaces",
-      "pages": [
-        "protocol-data",
-        "protocol-driver",
-        "protocol-permission",
-        "protocol-ui",
-        "protocol-system",
-        "protocol-auth",
-        "protocol-kernel",
-        "protocol-hub",
-        "protocol-ai",
-        "protocol-api",
-        "protocol-automation"
-      ]
-    },
+    "protocol-data",
+    "protocol-driver",
+    "protocol-permission",
+    "protocol-ui",
+    "protocol-system",
+    "protocol-auth",
+    "protocol-kernel",
+    "protocol-hub",
+    "protocol-ai",
+    "protocol-api",
+    "protocol-automation",
     "plugin-architecture",
     "security_architecture",
     "enterprise-patterns",