fix(podcasts+ui): user-test round 3 — five browser-reported defects

1. Add-modal 'Download order' never revealed: the CSS sibling selector
   (#podcast-download-all:checked ~ .podcast-add-order) can't fire —
   the checkbox was nested inside a wrapper div, so the select row was
   no SIBLING of the input. Restructured: input, label, and order row
   are now siblings under one flex-wrap wrapper.

2. Order + auto-download dropdowns always displayed the LAST option
   ('Newest first'/'Newest') regardless of the saved value: templ's
   selected={ boolExpr } compiles to selected="false" — and the mere
   PRESENCE of the attribute selects the option, so every option was
   selected and the browser honored the last. Sweep to the boolean-
   attribute form selected?={...} (omits on false) across
   podcast_detail (14), book_detail_modals (10: manga type/reading
   direction selects + abridged/explicit checkboxes — same defect,
   always-checked), collection_modal (2: hide-finished/show-up-next
   always-checked). Values were SAVING correctly all along; this was
   pure display. audio_reader/collections :selected/:checked are
   Alpine bindings — unaffected.

3. Remove Feed (and every hx-confirm) still showed the browser dialog
   for signed-in users: the global confirm modal rendered at the end
   of SidebarSignIn — signed-IN pages have no SidebarSignIn, so no
   #confirm-modal existed and confirmDialog() degraded to
   window.confirm. Moved the modal into Header proper (rendered on
   every page, after </aside>).

4. Facet bar at scale: values now carry feed COUNTS, sort by frequency
   DESC then alphabetically, cap at 6 chips per group flat, and the
   rest collapse into a native <details> '+N more' expander — hundreds
   of hosts/tags degrade gracefully instead of a wall of chips.

Verified live on the dev instance (order select reflects the saved
override, override row persists, reveal fires, modal renders on
signed-in pages). Podcast + logout + media-pin suites green; vitest
167 green.

templates/collection_modal.templ

@@ -75,12 +75,12 @@ templ CollectionModal(collection CollectionData) {
 						<div class="mb-4 space-y-2">
 							<label class="flex items-center gap-2 text-sm" style="color: var(--text-primary);">
 								<input type="hidden" name="hide_finished" value="false"/>
-								<input type="checkbox" name="hide_finished" value="true" checked={ collection.HideFinished } class="h-4 w-4 accent-current"/>
+								<input type="checkbox" name="hide_finished" value="true" checked?={ collection.HideFinished } class="h-4 w-4 accent-current"/>
 								<span>Hide finished books (reading-queue mode)</span>
 							</label>
 							<label class="flex items-center gap-2 text-sm" style="color: var(--text-primary);">
 								<input type="hidden" name="show_up_next" value="false"/>
-								<input type="checkbox" name="show_up_next" value="true" checked={ collection.ShowUpNext } class="h-4 w-4 accent-current"/>
+								<input type="checkbox" name="show_up_next" value="true" checked?={ collection.ShowUpNext } class="h-4 w-4 accent-current"/>
 								<span>Show Up Next strip</span>
 							</label>
 						</div>