fix(filter-builder): id labels resolve at render — refresh keeps names

Refresh showed raw uuids in id-kind value cells (feed/library/
collection/added_by). Two defects, one story:

1. Only ids persist in filter trees; the client's id→label cache dies
   with the page. The quiet re-resolution fetch reused the suggest
   facet, whose rows are MEDIA-CONSTRAINED (INNER JOIN media_items +
   the tree's sibling rules as a constraint) — so an id whose media
   doesn't match got no row and no label. Live repro: "feed in [A,B,C]
   AND title contains Chapter" labeled one feed of three (live-request
   evidence: 200 with total:1). A label is a property of the entity
   row, not of what currently matches.

   Fix: pages that render a tree resolve labels SERVER-SIDE at render
   and embed the map on the mount (data-id-labels) — the collection
   editor (stored tree) and the bookshelf (URL qf). New
   SearchService.FilterTreeLabels reads the entity tables with no
   media join and no tree constraint; scoping rides the request
   identity through the scoped handle (podcast_feeds/collections RLS —
   an invisible id resolves to nothing; pinned), libraries mirror the
   facet's visibility join. A feed with ZERO episodes resolves its
   title — pinned; that case was structurally impossible before.

2. The bookshelf drawer never hydrated at page load at all: the only
   load-time hydrate calls live in the PARENT's x-init
   (initBookshelf), and Alpine initializes parents before nested
   components — builderData() was null there, so hydrateFromForm
   no-oped and a URL-qf refresh left the drawer with an empty seeded
   rule while the grid stayed filtered. The drawer now hydrates in its
   OWN init when the mount carries no data-tree; the init-order
   contract is pinned in vitest (185/185).

The quiet suggest fetch remains only as a fallback for trees the SSR
never saw; embedded labels make it a no-op on refresh. Interactive
menus are untouched (their constrained, count-bearing behavior is
correct for choosing).

Pins: TestRulesPageEmbedsIdLabels (zero-episode feed labels at render,
bookshelf qf library label, hidden library NOT labeled);
filter/episode-tree/search-contract/RLS/playlist container slices
green; contract_pins entry documents the embed contract.

internal/router/helpers.go

@@ -297,6 +297,32 @@ func collectionDataFromRow(collection database.Collections, collectionID string,
 // detail page and the books-grid partial: smart evaluation, a dashboard
 // query section, or manual membership. Callers resolve the scope:
 // libUUID/libScope/isAll/scoped per their own resolution rules.
+// resolveTreeLabelsJSON — SSR id-label resolution for a page-rendered
+// filter tree: walks the tree's id-kind rules, resolves uuids to display
+// names through the search engine (RLS/visibility ride the request
+// identity), and returns the JSON map embedded into the builder mount.
+// Best-effort: any failure yields "{}" and the page renders with the
+// client's fallbacks intact (2026-11-01, filter_labels.go for the WHY).
+func resolveTreeLabelsJSON(c *echo.Context, cfg *Config, userID string, tree *services.FilterTree) string {
+	if tree == nil || len(tree.Children) == 0 {
+		return "{}"
+	}
+	userUUID, err := uuid.Parse(userID)
+	if err != nil {
+		return "{}"
+	}
+	labels := cfg.MediaHandler.SearchService().FilterTreeLabels(
+		c.Request().Context(), pgtype.UUID{Bytes: userUUID, Valid: true}, tree)
+	if len(labels) == 0 {
+		return "{}"
+	}
+	b, merr := json.Marshal(labels)
+	if merr != nil {
+		return "{}"
+	}
+	return string(b)
+}
+
 func (cfg *Config) collectionBooksForScope(c *echo.Context, userUUID uuid.UUID, collUUID pgtype.UUID, collection database.Collections, collectionID string, libUUID pgtype.UUID, libScope pgtype.UUID, scoped bool, visibleIDs []pgtype.UUID) (books []handlers.BookInfo, isSmart bool, errCode string) {
 	colService := cfg.CollectionHandler.CollectionService()
 	isSmart = services.IsCollectionSmart(collection)