refactor(docs): migrate existing content to v1 legacy structure

- Move all existing docs content (concepts, project, solution) to /docs/v1/
- Add legacy banner component to warn users about archived documentation
- Create v1 index page with legacy notice and redirect guidance
- Implement automatic banner display for all v1 paths
- Preserve all original content for reference during migration

This enables incremental content migration while maintaining access to
original documentation.

.vscode/settings.json

@@ -18,9 +18,5 @@
         "titleBar.activeForeground": "#15202b",
         "titleBar.inactiveBackground": "#61dafb99",
         "titleBar.inactiveForeground": "#15202b99"
-    },
-    // Markdown linting
-    "markdownlint.config": {
-        "extends": ".markdownlint.json"
     }
 }