feat(admin): display running version in footer and /health

Inline package.json version at bundle time via src/config/version.ts
(resolveJsonModule), surface it in the shared admin/status footer and
add it to the /health JSON so self-hosters can tell which build runs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/routes/admin/ui.tsx

@@ -3,6 +3,7 @@ import layoutCss from "../../styles/layout.css";
 import componentsCss from "../../styles/components.css";
 import utilitiesCss from "../../styles/utilities.css";
 import { interactiveScripts } from "../../scripts/index";
+import { APP_VERSION } from "../../config/version";
 import { FAVICON_PATH } from "../favicon";
 import { Env } from "../../types";
 import {
@@ -77,6 +78,10 @@ export const Layout = ({ title, label = "admin", children }: LayoutProps) => {
           >
             ♥ Sponsor
           </a>
+          <span class="site-footer-sep" aria-hidden="true">
+            ·
+          </span>
+          <span class="site-footer-version">v{APP_VERSION}</span>
         </footer>
       </body>
     </html>