test(podcasts): the briefing acceptance plays the born-reversed order

The §0-item-2 acceptance pin predates the chain-order system and
assumed the native default: it started the chain at feed position 1
and expected a forward hop. With the born-reversed default (d56031f3),
the page's first card is feed position 5 and the chain runs 5 → 1 —
the acceptance's MEANING is unchanged (play from the first card you
see, chained back-to-back within the live briefing set); the fixture
card it starts from flipped accordingly. Changelogged.

This was the only failure in the full-suite validation run (154s,
green) — the first whole-suite pass across today's four units
(chips, label endpoint, apply-path seed, born-reversed acceptance).

cmd/server/tests/podcast_test.go

@@ -884,9 +884,10 @@ func TestPodcastSmartCollections(t *testing.T) {
 
 	t.Run("acceptance_briefing_plays_back_to_back", func(t *testing.T) {
 		// ALL mode is the stored tree root: today's unplayed feed-A
-		// episodes = aNew + aNew2, chained in native feed order. Playing
-		// the FIRST match (the header's Play-as-Sequence target) must
-		// chain into the second.
+		// episodes = aNew + aNew2. BORN REVERSED (2026-11-01): the
+		// collection's default chain order is reverse, so the page's
+		// first card is feed position 5 (aNew2) and the chain runs
+		// 5 → 1 — book order for feeds that list newest-first.
 
 		// The detail page (smart branch, All Libraries view) renders
 		// episode cards with the play affordance + the header button.
@@ -905,16 +906,17 @@ func TestPodcastSmartCollections(t *testing.T) {
 		assert.Contains(t, html, "Play as Sequence", "smart collections play as a sequence too")
 		assert.Contains(t, html, "?queue=collection:"+collID, "smart episode cards chain through the queue param")
 
-		// Start from the first briefing match (feed position 1): index 1
-		// of 2, next = the second, both hops carrying the queue param.
+		// Start from the page's FIRST card (feed position 5 under the
+		// reversed default): index 1 of 2, next = feed position 1, both
+		// hops carrying the queue param.
 		code, body = podcastAuthed(t, setup, regToken, "GET",
-			"/readers/"+uuid.UUID(aNew.ID.Bytes).String()+"?queue=collection:"+collID, "")
+			"/readers/"+uuid.UUID(aNew2.ID.Bytes).String()+"?queue=collection:"+collID, "")
 		require.Equal(t, http.StatusOK, code)
 		html = string(body)
 		assert.Contains(t, html, esc(`"source":"collection"`))
 		assert.Contains(t, html, esc(`"episode_index":1`))
 		assert.Contains(t, html, esc(`"index_total":2`), "exactly the briefing set: aOld fails <7d, aPlayed fails unplayed, aPending is un-downloaded, bEp is RLS-dropped")
-		assert.Contains(t, html, esc(`"next_url":"/readers/`+uuid.UUID(aNew2.ID.Bytes).String()+`?queue=collection:`+collID+`"`))
+		assert.Contains(t, html, esc(`"next_url":"/readers/`+uuid.UUID(aNew.ID.Bytes).String()+`?queue=collection:`+collID+`"`))
 		assert.NotContains(t, html, `id="player-order-select"`, "computed order — the order control stays hidden (R1)")
 	})