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/data/_system/ds.config.json

@@ -0,0 +1,33 @@
+{
+  "name": "dss-system",
+  "version": "1.0.0",
+  "description": "DSS internal design system (dogfooding)",
+  "skin": "base",
+  "base_theme": "light",
+  "targets": [
+    {
+      "name": "admin-ui",
+      "path": "./admin-ui",
+      "type": "web-app",
+      "framework": "vanilla"
+    },
+    {
+      "name": "storybook",
+      "path": "./storybook",
+      "type": "documentation",
+      "framework": "storybook"
+    }
+  ],
+  "output": {
+    "tokens_dir": "./.dss/data/_system/tokens",
+    "themes_dir": "./.dss/data/_system/themes",
+    "components_dir": "./.dss/data/_system/components",
+    "formats": ["css", "scss", "json"]
+  },
+  "figma": {
+    "files": [],
+    "auto_sync": false
+  },
+  "created_at": "$(date -Iseconds)",
+  "updated_at": "$(date -Iseconds)"
+}