feat(podcasts): real-time episode list — byte progress bars, direct swaps (issues #1/#3)

WHY: downloads needed manual refreshes to see progress; the 204 +
HX-Trigger event indirection missed its listener, and the worker
buffered whole enclosures so no progress existed to show.

- Worker streams enclosures to disk through a counting loop (64KiB
  chunks, scheme/redirect/size guards preserved) with an in-memory
  per-episode progress snapshot (received/total; total from
  Content-Length, seeded by the feed's declared length). Deliberately
  transient — the DB row state remains the durable truth.
- Episode-list renderer seam: the router injects a closure into
  PodcastHandler (handlers can't import templates — MediaDetail cycle)
  so htmx download/retry/Download All/refresh/order/policy actions
  answer with the REFRESHED partial directly (200, hx-target=
  #episode-list) — no events to miss. Non-HX callers keep JSON; tests
  without a renderer keep 204+trigger.
- Polling tightens to 2s while downloads are active; downloading rows
  render a percentage bar + MB counter (quote-free inline style per
  templ gotcha #8) or an indeterminate bar when the server sends no
  length.
- Issue #3: Download All (button AND the add-feed checkbox) flips the
  CALLER's subscription policy to 'all' — per-user, never global (D6:
  files shared, policies not) — and the auto-download select
  out-of-band-swaps so the dropdown shows what the user is getting.
  They can turn it down afterwards; the flip is honest communication,
  not coercion (user-approved 2026-10-29).

PINs: Download All with HX answers 200 + episode-list + oob select and
flips newest → all; add-feed download_all sets policy all.

cmd/server/tests/podcast_test.go

@@ -730,3 +730,79 @@ func TestPodcastPageSearchEpisodes(t *testing.T) {
 	assert.Contains(t, body, "matching episode",
 		"the match count renders on the card")
 }
+
+// ---- issue #3: Download All flips the CALLER's auto-download to all ----
+
+func TestPodcastDownloadAllPolicyFlip(t *testing.T) {
+	setup := setupTestServer(t)
+	regularID := getRegularUserID(t, setup.DB)
+	lib, _ := createPodcastsLibrary(t, setup, "test Flip Podcasts")
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("/feed.xml", func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "application/rss+xml")
+		_, _ = w.Write([]byte(podcastFixture("Flip Feed", map[string]string{"f-1": "Flip One"})))
+	})
+	srv := swapFeedServer(t, mux.ServeHTTP)
+
+	libID := uuid.UUID(lib.ID.Bytes).String()
+	regularPG := pgtype.UUID{Bytes: regularID, Valid: true}
+
+	t.Run("add_feed_with_download_all_sets_policy_all", func(t *testing.T) {
+		resp, body := podcastAuthed(t, setup, setup.RegularToken, "POST", "/api/podcasts/feeds",
+			fmt.Sprintf(`{"library_id":%q,"url":%q,"download_all":true}`, libID, srv.URL+"/feed.xml"))
+		require.Equal(t, http.StatusCreated, resp, string(body))
+
+		sub, err := setup.DB.GetPodcastSubscription(rls.WithUser(context.Background(), regularPG), database.GetPodcastSubscriptionParams{
+			UserID: regularPG, FeedID: func() pgtype.UUID {
+				feeds, _ := setup.DB.ListPodcastFeedsForPolling(rls.WithUser(context.Background(), regularPG))
+				for _, f := range feeds {
+					if f.Title == "Flip Feed" {
+						return f.ID
+					}
+				}
+				return pgtype.UUID{}
+			}(),
+		})
+		require.NoError(t, err)
+		assert.Equal(t, "all", sub.AutoDownload, "PIN: the add-feed checkbox flips the caller's policy to all")
+	})
+
+	t.Run("download_all_button_flips_policy_and_returns_oob_select", func(t *testing.T) {
+		// Set the policy to newest first: the flip must override it.
+		feeds, _ := setup.DB.ListPodcastFeedsForPolling(rls.WithUser(context.Background(), regularPG))
+		var feedID pgtype.UUID
+		for _, f := range feeds {
+			if f.Title == "Flip Feed" {
+				feedID = f.ID
+			}
+		}
+		_, err := setup.DB.UpdatePodcastSubscription(rls.WithUser(context.Background(), regularPG), database.UpdatePodcastSubscriptionParams{
+			UserID: regularPG, FeedID: feedID,
+			DisplayName: pgtype.Text{}, AutoDownload: "newest",
+			AutoDownloadCount: pgtype.Int4{Int32: 3, Valid: true},
+		})
+		require.NoError(t, err)
+
+		feedIDStr := uuid.UUID(feedID.Bytes).String()
+		req, _ := http.NewRequest(http.MethodPost,
+			setup.Server.URL+"/api/podcasts/feeds/"+feedIDStr+"/episodes/all/download", nil)
+		req.Header.Set("Authorization", "Bearer "+setup.RegularToken)
+		req.Header.Set("HX-Request", "true")
+		hxResp, err := http.DefaultClient.Do(req)
+		require.NoError(t, err)
+		defer func() { _ = hxResp.Body.Close() }()
+		require.Equal(t, http.StatusOK, hxResp.StatusCode, "HX action answers with the refreshed partial")
+		var buf bytes.Buffer
+		_, _ = buf.ReadFrom(hxResp.Body)
+		body := buf.String()
+		assert.Contains(t, body, `id="episode-list"`, "direct swap: the episode list partial IS the response")
+		assert.Contains(t, body, `hx-swap-oob="true"`, "issue #3: the policy select rides along out-of-band")
+
+		sub, err := setup.DB.GetPodcastSubscription(rls.WithUser(context.Background(), regularPG), database.GetPodcastSubscriptionParams{
+			UserID: regularPG, FeedID: feedID,
+		})
+		require.NoError(t, err)
+		assert.Equal(t, "all", sub.AutoDownload, "PIN: Download All flips newest → all (dynamic + visible)")
+	})
+}