feat(podcasts): Download All queues in the LISTENING order + add-modal order dropdown

Download All previously queued in feed-native order — 'getting the
last chapter first doesn't help me'. Now the queue follows the feed's
effective listening order (§0 item 5b): QueueFeedDownloadsAs reads the
CALLER's order override and runs episodes through services.OrderEpisodes
(same helper as the sequence/reader/page surfaces — the consolidation
from item 5a landed with the reverse-order commit). Queue tickets
(SEQUENCE-stamped, item 4) make that enqueue order the claim order, so
chapters land in the order you'll actually listen.

Add modal (§0 item 5c): with 'Download all episodes now' checked, a
'Download order' select appears (pure-CSS :checked sibling reveal — no
JS island, CSP-clean). Its choice is the feed's INITIAL order override
(reader_settings upsert; 'feed' = no row) AND the queue order for the
initial batch. Per-book by design: the override IS the download order.

Test TestPodcastAddModalDownloadOrder: add with download_all+reverse →
the override row exists AND persisted tickets run position 3→1. Tickets
are asserted (not live queued rows) because the shared dev server's
worker legitimately races this test's queue — tickets survive every
state flip.

internal/handlers/podcast.go

@@ -90,6 +90,11 @@ type AddPodcastFeedRequest struct {
 	LibraryID   string   `json:"library_id" form:"library_id" validate:"required"`
 	URL         string   `json:"url" form:"url" validate:"required"`
 	DownloadAll FlexBool `json:"download_all" form:"download_all"`
+	// DownloadOrder: the initial listening order for THIS feed, applied
+	// only with DownloadAll (§0 item 5c) — it both seeds the queue in
+	// listening order and sets the caller's order override. ""/"feed" =
+	// no override row.
+	DownloadOrder string `json:"download_order,omitempty" form:"download_order"`
 }
 
 // FlexBool binds checkbox-style booleans on every wire. echo bool-binds
@@ -182,7 +187,23 @@ func (h *PodcastHandler) AddFeed(c *echo.Context) error {
 		return podcastErrorResponse(c, err)
 	}
 	if req.DownloadAll && res.Feed != nil {
-		if _, err := h.worker.QueueFeedDownloads(c.Request().Context(), res.Feed.ID); err != nil {
+		// §0 item 5c: the add modal's order dropdown is the feed's
+		// INITIAL listening order — it IS the download order (the queue
+		// seeds in that order below). 'feed'/'native' = no override row.
+		order := "native"
+		switch req.DownloadOrder {
+		case "reverse", "oldest", "newest":
+			order = req.DownloadOrder
+			payload, _ := json.Marshal(map[string]string{"order": order})
+			if err := h.db.UpsertUserSettingByKey(c.Request().Context(), database.UpsertUserSettingByKeyParams{
+				UserID: user.ID, SettingKey: podcastOrderSettingKey(res.Feed.ID.String()), SettingValue: payload,
+			}); err != nil {
+				// subscription + queue stand; the dropdown just won't
+				// preselect it (surfaced on the next order set).
+				_ = err
+			}
+		}
+		if _, err := h.worker.QueueFeedDownloadsAs(c.Request().Context(), user.ID, res.Feed.ID); err != nil {
 			// subscription stands; download-all failure surfaces via the
 			// episode list states.
 		}
@@ -412,7 +433,8 @@ func (h *PodcastHandler) DownloadEpisodes(c *echo.Context) error {
 	eidRaw := c.Param("eid")
 	if eidRaw == "all" {
 		// Download All affordance: exactly the non-downloaded set (pin).
-		queued, err := h.worker.QueueFeedDownloads(ctx, feedID)
+		// Queues in the CALLER's listening order (§0 item 5b).
+		queued, err := h.worker.QueueFeedDownloadsAs(ctx, user.ID, feedID)
 		if err != nil {
 			return podcastErrorResponse(c, err)
 		}