feat(collections): the rules-Apply path seeds the reversed default too

The creation seed (d56031f3) covered born-smart collections; a STATIC
collection that becomes smart through the rules editor's Apply landed
without any curated order — its dropdown stayed "Feed order" while
every other podcast smart collection opened reversed. Same decision,
same guardrails (2026-11-01 user approved closing this gap): a PUT
carrying an episodes-scope tree seeds chain_order=reverse only when
neither the request NOR the stored view_settings names one — a
deliberate native (client-sent or saved) is never clobbered, and
books-scope trees seed nothing.

Pins: apply-seeds-when-unordered, respects-stored-native,
respects-client-native (TestSmartCollectionBornReversed now covers
both seed paths); changelogged in contract_pins.

cmd/server/tests/podcast_test.go

@@ -2414,6 +2414,43 @@ func TestSmartCollectionBornReversed(t *testing.T) {
 		assert.NotContains(t, string(body), `"chain_order"`,
 			"static collections get no chain_order seed")
 	})
+
+	// The creation seed's twin (2026-11-01): APPLYING an episodes tree
+	// to a collection with no curated order seeds reverse — a static
+	// collection becoming smart lands with the same default a
+	// born-smart one gets. Explicit values (client-sent or stored) are
+	// never clobbered.
+	t.Run("apply_path_seeds_when_unordered", func(t *testing.T) {
+		id := create(t, `{"name":"test BornRev Apply `+t.Name()+`"}`)
+		code, body := podcastAuthed(t, setup, regToken, "PUT", "/api/collections/"+id,
+			`{"name":"test BornRev Apply `+t.Name()+`","filter_tree":{"scope":"episodes","mode":"all","children":[]}}`)
+		require.Equal(t, http.StatusCreated, code, "%s", string(body))
+		_, body = podcastAuthed(t, setup, regToken, "GET", "/api/collections/"+id, "")
+		assert.Contains(t, string(body), `"chain_order":"reverse"`,
+			"applying an episodes tree to an unordered collection seeds reverse")
+	})
+
+	t.Run("apply_path_respects_stored_native", func(t *testing.T) {
+		id := create(t, `{"name":"test BornRev KeepNative `+t.Name()+`","view_settings":{"chain_order":"native"}}`)
+		code, body := podcastAuthed(t, setup, regToken, "PUT", "/api/collections/"+id,
+			`{"name":"test BornRev KeepNative `+t.Name()+`","filter_tree":{"scope":"episodes","mode":"all","children":[]}}`)
+		require.Equal(t, http.StatusCreated, code, "%s", string(body))
+		_, body = podcastAuthed(t, setup, regToken, "GET", "/api/collections/"+id, "")
+		assert.Contains(t, string(body), `"chain_order":"native"`,
+			"a stored explicit chain_order is never clobbered by the apply seed")
+		assert.NotContains(t, string(body), `"chain_order":"reverse"`)
+	})
+
+	t.Run("apply_path_respects_client_native", func(t *testing.T) {
+		id := create(t, `{"name":"test BornRev ClientNative `+t.Name()+`"}`)
+		code, body := podcastAuthed(t, setup, regToken, "PUT", "/api/collections/"+id,
+			`{"name":"test BornRev ClientNative `+t.Name()+`","filter_tree":{"scope":"episodes","mode":"all","children":[]},"view_settings":{"chain_order":"native"}}`)
+		require.Equal(t, http.StatusCreated, code, "%s", string(body))
+		_, body = podcastAuthed(t, setup, regToken, "GET", "/api/collections/"+id, "")
+		assert.Contains(t, string(body), `"chain_order":"native"`,
+			"the client's explicit chain_order wins over the apply seed")
+		assert.NotContains(t, string(body), `"chain_order":"reverse"`)
+	})
 }
 
 // ---- label endpoint: names id-kind values for client-held trees ----