feat(docs): mkdocs-style documentation site served at /docs

Full documentation hub replacing the release-notes-only view:
- Handbook pages (docs/handbook) for all features and admin/betrieb
- API reference generated from lib/api-spec/openapi.yaml via
  scripts/src/generate-docs.mjs (replaces sync-release-docs.mjs):
  endpoints, schemas/fields, search index, per-release snapshots
- mkdocs layout: sidebar nav, right TOC with scrollspy, search overlay,
  version dropdown, repo link
- FieldHelp (?) buttons in forms linking to reference field docs
- v0.7.0 release notes backfilled, v0.8.0 release notes added

artifacts/toolrate/src/App.tsx

@@ -47,8 +47,7 @@ function Router() {
       <Route path="/admin" component={Admin} />
       <Route path="/admin/redundancy" component={Redundancy} />
       <Route path="/trash" component={Trash} />
-      <Route path="/docs" component={Docs} />
-      <Route path="/docs/:version" component={Docs} />
+      <Route path="/docs/*?" component={Docs} />
       <Route component={NotFound} />
     </Switch>
   );