chore(templ): warn against change handlers on the bookshelf library select

The bookshelf select (#library-select) sits inside the htmx filter
form and the SSR route honors ?offset= — wiring a change handler or
hx-trigger="change" on it would let header.ts's synthetic restore
event re-fetch the grid at offset 0, the same stomp class that broke
the /series paginator. Comment-only guard; regenerated
bookshelf_templ.go carries it into the emitted markup.

templates/bookshelf.templ

@@ -139,6 +139,12 @@ templ BookShelf(
 							<div class="p-6 space-y-5">
 								<div>
 									<label class="block text-xs font-semibold uppercase tracking-wide mb-2" style="color: var(--text-secondary)">Library</label>
+									<!-- Do NOT wire a `change` handler (or hx-trigger="change")
+										on this select: header.ts restoreLibrarySelection may
+										fire a synthetic change on page load, and a handler
+										here would re-fetch the grid at offset 0, stomping
+										SSR pagination (?offset=). User changes go through
+										bookshelf.ts's own wiring only. -->
 									<select id="library-select" name="library_id" class="input">
 										if len(libraries) == 0 {
 											<option value="">No libraries available</option>