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.

templates/podcast_types.go

@@ -91,10 +91,23 @@ type PodcastEpisodeRow struct {
 	Size         string // human MB/GB when known
 	PlayURL      string // reader URL (audio reader serves episodes like audiobooks)
 	CoverImage   string
-	ProgressPct  float64
 	Downloaded   bool
 	DownloadState string // pending|queued|downloading|downloaded|failed
 	DownloadError string
+
+	// Playback progress (reading_progress; the row badge) — reuses the
+	// ProgressPct field below when the row is downloading? No: keep the
+	// two concerns separate (issue #1).
+	ListenPct float64
+
+	// Live byte progress for rows in the downloading state (issue #1):
+	// the worker's in-flight snapshot. ProgressKnown=false renders the
+	// indeterminate bar; ProgressPct (0-100) drives the width when the
+	// total is authoritative.
+	ProgressKnown    bool
+	ProgressPct      float64
+	ProgressReceived int64
+	ProgressTotal    int64
 }
 
 // StateBadge renders the canonical state label.
@@ -172,6 +185,10 @@ type PodcastDetailData struct {
 	Order     string // native | oldest | newest (the caller's override)
 	IsAdmin   bool
 	IsSerial  bool // serial/audiobook feeds get the oldest-first suggestion (D5)
+	// SubscriberCount (issue #7): drives the last-subscriber
+	// unsubscribe flow — the sole subscriber who is an admin gets the
+	// three-choice modal (unsubscribe / remove feed / cancel).
+	SubscriberCount int
 }
 
 // podcastInt renders an int for templates.