feat: Add DSS infrastructure, remove legacy admin-ui code

- Remove legacy admin-ui/js/ vanilla JS components
- Add .dss/ directory with core tokens, skins, themes
- Add Storybook configuration and generated stories
- Add DSS management scripts (dss-services, dss-init, dss-setup, dss-reset)
- Add MCP command definitions for DSS plugin
- Add Figma sync architecture and scripts
- Update pre-commit hooks with documentation validation
- Fix JSON trailing commas in skin files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

dss-claude-plugin/core/skins/classic.json

@@ -1,21 +1,9 @@
 {
   "meta": {
     "id": "classic",
-    "version": "2.0.0",
-    "parent": "base"
+    "version": "1.0.0",
+    "description": "Classic skin - awaiting Figma sync",
+    "extends": "base"
   },
-  "tokens": {
-    "colors": {
-      "primary": "#3B82F6",
-      "secondary": "#10B981",
-      "danger": "#EF4444",
-      "background": "#F3F4F6",
-      "surface": "#FFFFFF",
-      "text": "#1F2937"
-    },
-    "borderRadius": {
-      "default": "0.25rem",
-      "lg": "0.5rem"
-    }
-  }
+  "tokens": {}
 }