Keep the sidebar in view on long pages

Beside the page, the sidebar now stays in place while the page scrolls,
so the account link and Sign out are always visible; it scrolls by
itself in very short windows. On a phone it still stacks above the page.
Also show the version with one 'v': release builds already start with it.

app.js

@@ -518,7 +518,7 @@
           h('span', null, h('strong', null, me.name), h('span', null, 'My account')))),
         h('div', { class: 'footrow' },
           h('button', { type: 'button', onClick: logout }, 'Sign out'),
-          h('span', null, 'v' + me.version))));
+          h('span', null, 'v' + me.version.replace(/^v/, '')))));
     main = h('main', { class: 'main', id: 'main' });
     app.replaceChildren(h('div', { class: 'shell' }, nav, main));
     refreshSide();