feat(facets): all-facets panel with under-filter counts (faceted plan Phase 7)

The 9 Batch A facets could not be SET from the web UI, the facets
endpoint had no in-app consumer, and the registry's libraryTypes hints
rendered nowhere. This phase closes all three.

- ONE UNION-ALL sqlc query (FacetCountsUnderFilters) computes all 14
  listable facets in a single round trip: each arm omits its OWN
  facet's filter block and carries every other registered facet's
  block (copied mechanically from SearchMediaItemsUnified) — classic
  faceted semantics: with filters active each facet counts under the
  others; with none, blocks are neutral and the counts are the v1
  global-per-library ones. One query serves both cases. The 14
  per-column Batch C queries are deleted.
- Endpoint: no facet param → the new all-facets shape
  ({facets: {param: [{value, display?, count}]}}), filters bound via
  the shared ParseMediaSearchParams, library_id optional (the
  All-Libraries view, family lens still enforced); facet=X keeps the
  pinned single-facet shape (now routed through the same query with
  neutral filters).
- SSR partial GET /media-items/facet-panel: templ renders the drawer's
  value lists — registry order, Batch D library-type scoping
  (FacetsForLibraryType: manga_type on manga, reading_direction on
  manga+comics, narrator on audiobooks; All view = union), prettified
  genre labels + language display names, active values marked. Family
  lens: out-of-set explicit library_id is 403.
- Drawer wiring: the panel fetches on drawer open and after every
  apply with the CURRENT filter query string; a value click toggles
  that facet's comma-joined filter (hidden input where the drawer has
  no field — same as deep links) and re-applies the form; chips and
  URL stay in sync. Values are server-rendered (rendering doctrine);
  bookshelf.ts owns only the click/fetch orchestration.
- prettifyGenre moves to internal/utils as the canonical
  implementation (services' display enrichment shares it; templ wraps
  it; the TS port in bookshelf.ts is unchanged).
- Drift guard extended: FacetCountsUnderFiltersParams must carry every
  registry facet's param, the bools as pgtype.Bool.

Tests: under-filter exactness (own-block omission, OR-within,
AND-across), family lens (hidden values absent; 403 on both shapes),
all-shape + pinned-shape coexistence, partial rendering with Batch D
scoping + active marking + 403. Full container suite green except the
documented pre-existing TestAdminCreateUser red.

templates/bookshelf.templ

@@ -62,7 +62,7 @@ templ BookShelf(
 							<option value="created_at DESC">Date Added</option>
 							<option value="page_count DESC">Page Count</option>
 						</select>
-						<button type="button" @click="filtersOpen = true" class="btn btn-secondary">
+						<button type="button" @click="filtersOpen = true; loadFacetPanel()" class="btn btn-secondary">
 							@Icon("filter", "h-4 w-4")
 							<span>Filters</span>
 						</button>
@@ -279,6 +279,19 @@ templ BookShelf(
 										/>
 									</template>
 								</div>
+								<div>
+									<label class="block text-xs font-semibold uppercase tracking-wide mb-2" style="color: var(--text-secondary)">Browse by facet</label>
+									<!-- Phase 7: facet values are server data — this partial is
+										rendered by templ (templates/facet_panel.templ) and fetched
+										with the CURRENT filter query string on drawer open and
+										after every apply, so counts are computed under the active
+										filters. A value click toggles that facet's filter input
+										(hidden where the drawer has no field) and re-applies the
+										form — bookshelf.ts owns the click, templ owns the look. -->
+									<div id="facet-panel" class="space-y-2">
+										<p class="text-xs" style="color: var(--text-secondary);">Open the filters to browse facet values.</p>
+									</div>
+								</div>
 							</div>
 							<div class="sticky bottom-0 px-6 py-4 border-t" style="background-color: var(--bg-secondary); border-color: color-mix(in srgb, var(--text-primary) 7%, transparent);">
 								<button type="submit" @click="filtersOpen = false" class="btn btn-primary w-full">Apply Filters</button>