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.

internal/handlers/podcast.go

@@ -7,6 +7,7 @@
 package handlers
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"sort"
@@ -24,6 +25,55 @@ type PodcastHandler struct {
 	db       *database.Queries
 	podcasts *services.PodcastService
 	worker   *services.PodcastDownloadWorker
+
+	// episodeListRenderer renders the refreshed episode-list partial
+	// for htmx action responses (download/refresh/order/policy).
+	// Injected by the router at wiring time — the view assembly lives
+	// with the other templ view code (handlers must not import
+	// templates: templates imports handlers for MediaDetail). When nil
+	// (tests, API-only), htmx callers fall back to JSON + HX-Trigger.
+	episodeListRenderer EpisodeListRenderer
+}
+
+// EpisodeListRenderer renders the post-action episode list for an htmx
+// request. includePolicySelect additionally out-of-band-swaps the
+// auto-download select (Download All flips the caller's policy — the
+// dropdown must reflect it immediately, issue #3).
+type EpisodeListRenderer func(c *echo.Context, feedID string, includePolicySelect bool) error
+
+// SetEpisodeListRenderer wires the renderer (router-only; product wiring).
+func (h *PodcastHandler) SetEpisodeListRenderer(r EpisodeListRenderer) {
+	h.episodeListRenderer = r
+}
+
+// hxEpisodeList answers an htmx action with the refreshed partial when
+// a renderer is wired; otherwise falls back to 204 + HX-Trigger.
+func (h *PodcastHandler) hxEpisodeList(c *echo.Context, feedID string, includePolicySelect bool) error {
+	if h.episodeListRenderer != nil {
+		return h.episodeListRenderer(c, feedID, includePolicySelect)
+	}
+	return hxAccepted(c, "")
+}
+
+// flipSubscriptionToAll implements issue #3: Download All (button or
+// add-feed checkbox) sets the CALLER's subscription policy to 'all' —
+// per-user, never global (files are shared D6, policies are not). The
+// dropdown reflects it via the renderer's oob swap; the user can turn
+// it down afterwards.
+func (h *PodcastHandler) flipSubscriptionToAll(ctx context.Context, userID, feedID pgtype.UUID) {
+	sub, err := h.db.GetPodcastSubscription(ctx, database.GetPodcastSubscriptionParams{
+		UserID: userID, FeedID: feedID,
+	})
+	if err != nil || sub.AutoDownload == "all" {
+		return // not subscribed (admin pass-through) or already all
+	}
+	_, _ = h.db.UpdatePodcastSubscription(ctx, database.UpdatePodcastSubscriptionParams{
+		UserID:            userID,
+		FeedID:            feedID,
+		DisplayName:       sub.DisplayName,
+		AutoDownload:      "all",
+		AutoDownloadCount: pgtype.Int4{}, // all needs no count
+	})
 }
 
 func NewPodcastHandler(db *database.Queries, svc *services.PodcastService, worker *services.PodcastDownloadWorker) *PodcastHandler {
@@ -111,6 +161,9 @@ func (h *PodcastHandler) AddFeed(c *echo.Context) error {
 			// subscription stands; download-all failure surfaces via the
 			// episode list states.
 		}
+		// Issue #3: the checkbox means "everything, now AND going
+		// forward" — reflect it in the caller's subscription policy.
+		h.flipSubscriptionToAll(c.Request().Context(), user.ID, res.Feed.ID)
 	}
 	if isHXRequest(c) {
 		// Post-redirect-get: land on the new feed's page. Fetch errors
@@ -252,7 +305,7 @@ func (h *PodcastHandler) UpdateSubscription(c *echo.Context) error {
 	if isHXRequest(c) {
 		// Policy changes feed the auto-download union on the next poll.
 		_, _ = h.worker.ApplyAutoPolicies(ctx, feedID)
-		return hxAccepted(c, "")
+		return h.hxEpisodeList(c, feedID.String(), true)
 	}
 	return c.JSON(http.StatusOK, updated)
 }
@@ -291,7 +344,7 @@ func (h *PodcastHandler) RefreshFeed(c *echo.Context) error {
 		return podcastErrorResponse(c, err)
 	}
 	if isHXRequest(c) {
-		return hxAccepted(c, "")
+		return h.hxEpisodeList(c, feedID.String(), false)
 	}
 	return c.JSON(http.StatusOK, map[string]string{"message": "refreshed"})
 }
@@ -339,7 +392,10 @@ func (h *PodcastHandler) DownloadEpisodes(c *echo.Context) error {
 			return podcastErrorResponse(c, err)
 		}
 		if isHXRequest(c) {
-			return hxAccepted(c, "")
+			// Download All flips the caller's policy to all (issue #3)
+			// — the oob select keeps the dropdown honest.
+			h.flipSubscriptionToAll(ctx, user.ID, feedID)
+			return h.hxEpisodeList(c, feedID.String(), true)
 		}
 		return c.JSON(http.StatusAccepted, map[string]interface{}{"queued": queued})
 	}
@@ -351,7 +407,7 @@ func (h *PodcastHandler) DownloadEpisodes(c *echo.Context) error {
 		return podcastErrorResponse(c, err)
 	}
 	if isHXRequest(c) {
-		return hxAccepted(c, "")
+		return h.hxEpisodeList(c, feedID.String(), false)
 	}
 	return c.JSON(http.StatusAccepted, map[string]string{"message": "queued"})
 }
@@ -485,7 +541,7 @@ func (h *PodcastHandler) SetFeedOrder(c *echo.Context) error {
 		}
 	}
 	if isHXRequest(c) {
-		return hxAccepted(c, "")
+		return h.hxEpisodeList(c, feedID.String(), false)
 	}
 	return c.JSON(http.StatusOK, map[string]string{"order": req.Order})
 }