docs: move API reference to developer docs, add active nav state, remove package-lock.json

- Move API reference from user-docs to developer-docs section:
  - Change OpenAPI plugin docsPluginId from 'classic' to 'developer_docs'
  - Move api.mdx and update outputDir to developer_docs/api
  - Update all three API generation scripts to use new paths
  - Update sidebars, navbar items, and redirect targets
  - Add redirect from /user-docs/api to /developer-docs/api
  - Update .gitignore for new generated API path

- Add activeBaseRegex to navbar dropdowns so the active section
  highlights when browsing sub-pages (Users, Admins, Developers,
  Community)

- Fix dropdown active link styling to use primary color instead
  of being invisible (transparent)

- Remove accidental empty package-lock.json from repo root
  (added in SIP-32, 2019)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/sidebarTutorials.js

@@ -129,9 +129,21 @@ const sidebars = {
       ],
     },
     {
-      type: 'link',
+      type: 'category',
       label: 'API Reference',
-      href: '/user-docs/api',
+      link: {
+        type: 'doc',
+        id: 'api',
+      },
+      items: (() => {
+        try {
+          // eslint-disable-next-line @typescript-eslint/no-require-imports
+          return require('./developer_docs/api/sidebar.js');
+        } catch {
+          // Generated by `yarn generate:api-docs`; empty until then
+          return [];
+        }
+      })(),
     },
   ],
 };