When switching libraries via TypeScript, renderBookCard() built book
cards as <div> elements with data-action="view-book" for event
delegation, but the click handler was commented out — making books
unclickable after any library switch. The SSR path used proper <a> tags.
Now renderBookCard() wraps cards in <a href="/media/{id}"> to match the
SSR BookCard template, so book links work identically regardless of
whether content was server-rendered or client-rendered.
Also removed the dead view-book handler code and viewBook() stub.
Additionally fixed a listener re-registration bug where the input and
library-select change listeners were nested inside the click callback,
causing them to be registered N times after N clicks. Moved them to
initDashboard() scope so they register exactly once.