feat(podcasts): queue context source + player order control — item 2.2

Foundation rule R2 (§10): the queue context is the only queue, and
every producer emits the same shape. PodcastSequenceContext gains
source (feed|collection), feed_id, and order; the feed producer sets
them now — the collection producer (2.3) slots into the same shape
without the player ever special-casing beyond showing/hiding controls.

The player header gains the FEED-mode order control next to the
"Ep N/M" counter: a dropdown (native/reverse/oldest/newest) plus a
one-click reverse button. Both PUT the existing per-user feed order
override — the SAME state the feed page writes, so flipping it in the
player updates the feed page's dropdown too. The control renders only
when source=feed: a collection queue's order is curated content
(R1), never a listening preference. Behavior is hx-put +
hx-swap="none" (response discarded) with a module-level
htmx:afterRequest listener in audio.ts reloading the page — the
server re-renders prev/next/index in the new order; templ decides
what it looks like, JS only triggers the round trip (CSP-clean, no
inline handlers).

Pinned by TestPodcastPlayerOrderControl: the config JSON carries
source/feed_id/order/episode_index; the control renders feed-mode;
an order override re-renders with the dropdown reflecting it (data-
json pins must match templ's " attribute escaping).

cmd/server/tests/podcast_test.go

@@ -499,6 +499,67 @@ func TestReaderSettingsCompositeKeyHeadroom(t *testing.T) {
 	require.JSONEq(t, `{"order":"custom"}`, string(val))
 }
 
+// ---- item 2.2: queue context source + the player's feed-mode order
+// control (§10 R2) ----
+
+func TestPodcastPlayerOrderControl(t *testing.T) {
+	setup := setupTestServer(t)
+	lib, _ := createPodcastsLibrary(t, setup, "test PlayerOrder Podcasts")
+	feed, err := setup.DB.CreatePodcastFeed(adminSeedCtx(t, setup), database.CreatePodcastFeedParams{
+		LibraryID: lib.ID,
+		FeedUrl:   "https://feed.invalid/player-order.xml",
+		Title:     "PlayerOrder Feed",
+	})
+	require.NoError(t, err)
+	ep1 := upsertTestEpisode(t, setup, feed, "po-1", "PlayerOrder One", 1)
+	ep2 := upsertTestEpisode(t, setup, feed, "po-2", "PlayerOrder Two", 2)
+
+	// download_state is download-owned (write-after-success guard) —
+	// tests set it directly under the first-admin identity (raw-pool
+	// execs on a detached context hit RLS and silently write 0 rows).
+	adminScopeExec(t, setup, adminCtxValue(t, setup),
+		`UPDATE media_items SET download_state = 'downloaded', file_size = 1000
+		 WHERE id IN ($1, $2) AND source = 'podcast_episode'`, ep1.ID, ep2.ID)
+	subscribeRaw(t, setup, uuid.UUID(adminCtxValue(t, setup).Bytes), feed.ID)
+
+	feedID := uuid.UUID(feed.ID.Bytes).String()
+	ep1URL := "/readers/" + uuid.UUID(ep1.ID.Bytes).String()
+
+	// The reader page embeds the sequence config in a data-json
+	// ATTRIBUTE — templ HTML-escapes the quotes ("), so pins must
+	// match the escaped form.
+	esc := func(s string) string { return strings.ReplaceAll(s, `"`, """) }
+
+	t.Run("context_carries_feed_source", func(t *testing.T) {
+		code, body := podcastAuthed(t, setup, setup.Token, "GET", ep1URL, "")
+		require.Equal(t, http.StatusOK, code)
+		assert.Contains(t, string(body), esc(`"source":"feed"`), "queue context must carry its owner (§10 R2)")
+		assert.Contains(t, string(body), esc(`"feed_id":"`+feedID+`"`))
+		assert.Contains(t, string(body), esc(`"order":"native"`))
+		assert.Contains(t, string(body), esc(`"episode_index":1`))
+	})
+
+	t.Run("order_dropdown_renders_feed_mode", func(t *testing.T) {
+		code, body := podcastAuthed(t, setup, setup.Token, "GET", ep1URL, "")
+		require.Equal(t, http.StatusOK, code)
+		assert.Contains(t, string(body), `id="player-order-select"`, "feed-mode queue renders the player order control")
+		assert.Contains(t, string(body), `hx-put="/api/podcasts/feeds/`+feedID+`/order"`)
+		assert.Contains(t, string(body), "Reverse episode order", "quick reverse button present")
+	})
+
+	t.Run("order_override_hides_dropdown_after_switch", func(t *testing.T) {
+		// Switch the order the way the player does (the same endpoint;
+		// podcastAuthed sends JSON and the handler binds both shapes),
+		// then re-render: the dropdown must reflect the new value.
+		code, body := podcastAuthed(t, setup, setup.Token, "PUT", "/api/podcasts/feeds/"+feedID+"/order", `{"order":"reverse"}`)
+		require.Equal(t, http.StatusOK, code, "%s", string(body))
+		code, body = podcastAuthed(t, setup, setup.Token, "GET", ep1URL, "")
+		require.Equal(t, http.StatusOK, code)
+		assert.Contains(t, string(body), esc(`"order":"reverse"`))
+		assert.Contains(t, string(body), `<option value="reverse" selected`, "dropdown reflects the override")
+	})
+}
+
 // ---- download worker: state machine, idempotency, file layout ----
 
 func TestPodcastDownloadWorker(t *testing.T) {