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).

web/src/audio.ts

@@ -206,6 +206,21 @@ function fmtTime(seconds: number): string {
   return `${m}:${String(sec).padStart(2, "0")}`;
 }
 
+// Player order control (item 2.2, feed-mode only): the header's select
+// and reverse button PUT the feed's per-user order override (the same
+// endpoint the feed page writes) with hx-swap="none" — the response is
+// discarded, and THIS reload is the swap: the server re-renders the
+// sequence context (prev/next/index) in the new order. Rendered only
+// when the queue source is "feed" (§10 R2 — collection queues hide it).
+document.addEventListener("htmx:afterRequest", (e) => {
+  const target = e.target as HTMLElement | null;
+  if (!target || !target.matches("#player-order-select, [aria-label='Reverse episode order']"))
+    return;
+  const evt = e as CustomEvent<{ successful?: boolean }>;
+  if (!evt.detail?.successful) return;
+  window.location.reload();
+});
+
 Alpine.data("audioReader", () => ({
   mediaItemId: "",
   title: "",