Add page schemas and pages to model

Introduce page-type and page-descriptor JSON Schemas to describe UI pages (type enum: dataGrid, kanban, calendar). The PageDescriptor defines name, title, icon, type, entityName, order and a groupByProperty that is conditionally required when type is kanban. Update model.schema.json to add a pages array referencing the new page-descriptor schema so pages can be declared in the model.

lowcode/schema/definitions/page-descriptor.schema.json

@@ -0,0 +1,49 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "page-descriptor.schema.json",
+  "title": "PageDescriptor",
+  "description": "Describes a UI page bound to an entity",
+  "type": "object",
+  "properties": {
+    "name": {
+      "type": "string",
+      "description": "Unique URL-safe identifier for the page",
+      "minLength": 1
+    },
+    "title": {
+      "type": "string",
+      "description": "Display title for the menu item and page header",
+      "minLength": 1
+    },
+    "icon": {
+      "type": "string",
+      "description": "FontAwesome icon class (e.g., 'fa-solid fa-users')"
+    },
+    "type": {
+      "$ref": "page-type.schema.json"
+    },
+    "entityName": {
+      "type": "string",
+      "description": "Full name of the root entity this page displays (e.g., 'Namespace.EntityName')",
+      "minLength": 1
+    },
+    "groupByProperty": {
+      "type": "string",
+      "description": "Property name to group entities by (required for kanban). Must reference an enum property.",
+      "minLength": 1
+    },
+    "order": {
+      "type": "integer",
+      "description": "Menu sort order (lower values appear first)",
+      "default": 0
+    }
+  },
+  "required": ["name", "title", "type", "entityName"],
+  "if": {
+    "properties": { "type": { "const": "kanban" } }
+  },
+  "then": {
+    "required": ["groupByProperty"]
+  },
+  "additionalProperties": false
+}

lowcode/schema/definitions/page-type.schema.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "page-type.schema.json",
+  "title": "PageType",
+  "description": "The type of page to render",
+  "type": "string",
+  "enum": ["dataGrid", "kanban", "calendar"]
+}

lowcode/schema/model.schema.json

@@ -29,6 +29,13 @@
       "items": {
         "$ref": "definitions/endpoint-descriptor.schema.json"
       }
+    },
+    "pages": {
+      "type": "array",
+      "description": "List of UI pages that appear as menu items and define how entities are displayed",
+      "items": {
+        "$ref": "definitions/page-descriptor.schema.json"
+      }
     }
   },
   "additionalProperties": false