feat(podcasts): the rules page retires — the collection builder IS the filter builder (item 3.4)

The smart-collection editor at /collections/:id/rules now hosts the
SAME builder island as All-Books (FilterBuilderRows — the rows markup
extracted into one shared templ both mounts render; the shared
filterBuilderExtra component). One vocabulary, one engine, one row UI;
the collection differences are exactly three: the payload is the
collection's scope (episode trees get the episode fields — books
trees hide them), Apply writes the tree to the collection (PUT
filter_tree through the validated write path), and a legacy rules
array preloads as its CONVERTED tree (RulesToFilterTree rendered
server-side) so the upgrade lands at the first Apply — read-compat
never mutates data silently.

Retired with the page: the per-rule CRUD endpoints and test-rules
(their handler bodies, routes, api-docs rows, and the dead collections.ts
island functions — the file's LIVE halves, the collection modal/navigate/
grid-refresh, stay; the dead rules half went). match-mode endpoint and
preview survive (legacy channel + the dashboard custom-section-builder,
flagged for its own migration). Contract-pin changelog documents the
deletions per the asymmetry rule.

The builder component gains collection mounts: scopeKey (the row
universe for counts/apply), data-tree prefill, treeJSON (the apply
wire with scope riding the top level), and an apply hook (the page
owns the write; All-Books never sets one). ensureReadyRule defaults to
the scope's first field instead of hardcoding author.

Tests migrated onto trees: TestSmartCollections' live-membership /
reject-mutations / include-auto / system-collection subtests now drive
TREE collections; the deleted-endpoint subtests die with them.

docs/contract_pins.md

@@ -489,3 +489,28 @@ unified filter tree when the smart collection carries one (item 3.2 —
 tree-driven membership), `null` for legacy/static collections. The
 tree is the same qf DSL as saved filters (`{scope?, mode, children}`).
 Nothing removed, nothing renamed.
+
+## 2026-10-30 — rules endpoints RETIRED (filter-system unification, item 3.4)
+
+The per-rule CRUD endpoints and the preview endpoint are DELETED — the
+unified filter tree (item 3.2) is the only smart-membership authoring
+surface, and the rules PAGE is now the filter builder in the
+collection's scope:
+
+- `POST /api/collections/:id/rules`, `PUT/DELETE
+  /api/collections/:id/rules/:ruleId` — gone (legacy rule arrays still
+  EVALUATE until the collection is rewritten; conversions run at the
+  builder's first Apply via RulesToFilterTree).
+- `POST /api/collections/test-rules` — gone (the builder's live count
+  via /api/media-items/filter-count replaces the preview).
+- `POST /api/collections/preview` STAYS (the dashboard
+  custom-section-builder still consumes it — flagged for its own
+  migration, not silently broken).
+- Legacy compatibility KEPT: `auto_assign_rules` still round-trips in
+  the collections envelope; `PUT /api/collections/:id/match-mode`
+  still serves rules-array collections.
+
+Test-side deletions follow the asymmetry rule: subtests exercising the
+deleted endpoints are gone; their surviving SEMANTICS are pinned in
+their tree form (TestSmartCollections rewritten on trees,
+TestEpisodeCollectionsFilterTree, TestPodcastSmartCollections).