feat(podcasts): web UI — /podcasts page, feed detail, download lifecycle (task 1.9)

Rendering ownership holds throughout: every piece of server data is
templ-rendered; htmx swaps partials; the only TS is the Add-Feed modal
toggle + error surfacing (pure client-local state, bundled via
web/src/podcasts.ts with automatic bundle-hash stamping).

Sidebar: /podcasts nav entry (D13, between Series and Collections),
gated by a ShowPodcastsNav flag resolved centrally in
getTemplateUserWithTheme (one indexed COUNT — same class of
per-request lookup as the live-user guard). New 'podcast' icon.

/podcasts: header + Add Feed modal (htmx post → HX-Redirect to the
feed page; inline error surfacing on failure), subscription-scoped
search + facet bar (host/tag/language — server-side GET filters, no
JS), grid cards with download counts / new-episodes / complete /
explicit badges. Empty states for no-library (admin creates it first)
and no-subscriptions.

Feed detail: hero (artwork, host/publisher, tags, fetch state), action
row — Download All, Refresh, ORDER SELECTOR (D5 override), serial
one-click oldest-first suggestion (never silent), auto-download policy
select (D6), Unsubscribe (files retained), admin Remove Feed — gap
banner (D8 count), and the EPISODE LIST with the full lifecycle inline
(D8/D19): pending greyed + Download button (every non-downloaded
episode has one), queued/downloading pulse, failed RED + reason text +
Retry (same endpoint). The list is a self-refreshing partial: re-fetch
on the podcast:changed HX-Trigger and polls every 4s ONLY while the
server says downloads are active (it renders the polling variant).

API endpoints grew HX awareness: 204 + HX-Trigger podcast:changed (or
HX-Redirect for add/unsubscribe/remove) — the sanctioned Go-handler
response channels; JSON callers keep JSON. AddFeed result exposes the
fetch-error text for the redirect.

Dates render in the requesting user's timezone (D17) via
utils.FormatTimeInTimezone; episodes play through the existing
/readers/{id} audio reader (episodes ARE audiobook items — no new
player code day one). CSP tripwire (templates/csp_source_test.go)
passes: no inline scripts, no on*= handlers, no hx-on/js: vals.

internal/database/querier.go

@@ -61,10 +61,12 @@ type Querier interface {
 	// shares the directory; otherwise the sidecar goes to
 	// <basename>.opf so one book's metadata can never poison dir-mates.
 	CountOtherMediaItemsInDir(ctx context.Context, arg CountOtherMediaItemsInDirParams) (int32, error)
+	CountPodcastEpisodesForFeed(ctx context.Context, sourceFeedID pgtype.UUID) (int64, error)
 	CountPodcastFeedSubscribers(ctx context.Context, feedID pgtype.UUID) (int64, error)
 	// Sidebar/page gate (D13): >=1 podcasts-type library the user can see
 	// (COALESCE(is_visible,true) semantics — mirrors GetUserVisibleLibraries).
 	CountPodcastLibrariesForUser(ctx context.Context, userID pgtype.UUID) (int64, error)
+	CountQueuedEpisodes(ctx context.Context) (int64, error)
 	CountUndownloadedEpisodes(ctx context.Context, sourceFeedID pgtype.UUID) (int64, error)
 	// Count unlinked books for a device (ignored rows stay hidden)
 	CountUnlinkedBooks(ctx context.Context, deviceID pgtype.UUID) (int64, error)
@@ -199,6 +201,7 @@ type Querier interface {
 	// Delete unlinked book
 	DeleteUnlinkedBook(ctx context.Context, id pgtype.UUID) error
 	DeleteUser(ctx context.Context, id pgtype.UUID) error
+	DeleteUserSettingByKey(ctx context.Context, arg DeleteUserSettingByKeyParams) error
 	DeleteUserSystemCollection(ctx context.Context, arg DeleteUserSystemCollectionParams) error
 	// Device deletion (deregister on logout): detach the device's reading
 	// history instead of deleting it — these rows are real captured stats
@@ -443,6 +446,8 @@ type Querier interface {
 	// GetMediaScanState reads one item's manifest (per-item rescan paths
 	// and the manifest integration tests).
 	GetMediaScanState(ctx context.Context, mediaItemID pgtype.UUID) (MediaScanState, error)
+	// Sequential download worker's claim source (single worker, day one).
+	GetNextQueuedEpisode(ctx context.Context) (MediaItems, error)
 	GetNextRetryTime(ctx context.Context) (interface{}, error)
 	GetNotStartedItems(ctx context.Context, arg GetNotStartedItemsParams) ([]MediaItems, error)
 	// Get OPDS token
@@ -451,6 +456,9 @@ type Querier interface {
 	GetOpdsTokensByDevice(ctx context.Context, deviceID pgtype.UUID) ([]OpdsTokens, error)
 	GetPanelData(ctx context.Context, arg GetPanelDataParams) (PanelData, error)
 	GetPodcastEpisode(ctx context.Context, id pgtype.UUID) (MediaItems, error)
+	// Per-user progress for a feed's episodes (row badges + the Phase-2
+	// continue fields). reading_progress is UNIQUE per (media_item, user).
+	GetPodcastEpisodeProgress(ctx context.Context, arg GetPodcastEpisodeProgressParams) ([]GetPodcastEpisodeProgressRow, error)
 	GetPodcastFeed(ctx context.Context, id pgtype.UUID) (PodcastFeeds, error)
 	// URL-migration dedupe: same canonical guid within the library reuses
 	// the existing row.
@@ -561,6 +569,12 @@ type Querier interface {
 	// END instant (the push time; NULL falls back to created_at) — the same
 	// value the capture stamps every write with.
 	GetUserReadingSessionsRange(ctx context.Context, arg GetUserReadingSessionsRangeParams) ([]GetUserReadingSessionsRangeRow, error)
+	// ============================================================================
+	// GENERIC reader_settings KV (podcast order override, plan D5: key
+	// podcast_order:<feed_id>). The pre-existing reader_settings queries are
+	// hard-keyed to 'reader_settings'; these two are the generic form.
+	// ============================================================================
+	GetUserSettingByKey(ctx context.Context, arg GetUserSettingByKeyParams) ([]byte, error)
 	GetUserVisibleLibraries(ctx context.Context, userID pgtype.UUID) ([]GetUserVisibleLibrariesRow, error)
 	GetVisibleLibraryMediaCounts(ctx context.Context, userID pgtype.UUID) ([]GetVisibleLibraryMediaCountsRow, error)
 	// Smart ("dynamic") collections: rules are evaluated LIVE at render, so
@@ -724,7 +738,7 @@ type Querier interface {
 	// un-downloaded AND historical rows (fetcher persists metadata-only).
 	// RLS already restricts to the caller's subscriptions — the explicit
 	// source filter keeps scan items out of podcast search.
-	SearchMyPodcastEpisodes(ctx context.Context, dollar_1 interface{}) ([]MediaItems, error)
+	SearchMyPodcastEpisodes(ctx context.Context, searchQuery string) ([]MediaItems, error)
 	// Feed-title AND subscription-display-name search (D14) + the facet
 	// fields the podcasts page filters on.
 	SearchMyPodcastFeeds(ctx context.Context, arg SearchMyPodcastFeedsParams) ([]SearchMyPodcastFeedsRow, error)
@@ -863,6 +877,7 @@ type Querier interface {
 	// Ingest: insert or refresh the queue row for a device file that could not
 	// be identified. One row per (device, content_id); re-syncs bump last_seen.
 	UpsertUnlinkedBook(ctx context.Context, arg UpsertUnlinkedBookParams) (UnlinkedBooks, error)
+	UpsertUserSettingByKey(ctx context.Context, arg UpsertUserSettingByKeyParams) error
 }
 
 var _ Querier = (*Queries)(nil)