docs: add nodedc ui guideline registry

dc-ui-guideline/rules/ui-rules.json

@@ -0,0 +1,51 @@
+{
+  "schemaVersion": "0.1.0",
+  "rules": [
+    {
+      "id": "no-random-local-ui",
+      "severity": "error",
+      "text": "Do not create a local one-off UI element when a registry component exists."
+    },
+    {
+      "id": "no-outlines",
+      "severity": "error",
+      "text": "Visible browser outlines and hard colored outlines are forbidden. Use surface hover/focus states."
+    },
+    {
+      "id": "circle-actions",
+      "severity": "error",
+      "text": "Icon-only actions are circular controls. They use the shared control-ring size and 5px inset rules."
+    },
+    {
+      "id": "dropdowns-portal",
+      "severity": "error",
+      "text": "Dropdowns inside cards, tables, sidebars, sticky headers, and scroll containers render through a portal/fixed layer."
+    },
+    {
+      "id": "dropdowns-shared-engine",
+      "severity": "error",
+      "text": "Selection dropdowns and action dropdowns use the shared dropdown engine. Do not implement local outside-click and absolute inline menus."
+    },
+    {
+      "id": "matte-glass",
+      "severity": "error",
+      "text": "Popup, dropdown, modal, sidebar, and settings surfaces use dark matte glass with blur, not plain transparency or light foreign backgrounds."
+    },
+    {
+      "id": "status-pills",
+      "severity": "error",
+      "text": "Statuses use the shared status-tone palette, centered label, no outline, and fixed status control geometry."
+    },
+    {
+      "id": "admin-tables",
+      "severity": "warning",
+      "text": "Admin data screens use AdminTable anatomy: table-shell, toolbar, editable cells, circular actions, and shared status/date controls."
+    },
+    {
+      "id": "taskmanager-calendar",
+      "severity": "warning",
+      "text": "Calendar popovers must follow the Task Manager nodedc-calendar-shell and portal dropdown pattern."
+    }
+  ]
+}
+