feat(audiobooks): Batch A — foundation, m4b ingest, playback sync, web player

Phase 1 (foundation): 'audiobooks' library type seeded (schema + DB);
audio_metadata JSONB on media_items (the kobo_metadata precedent —
only audio paths read it); reading_progress.audio_offset_seconds for
the honest {chapter, offset} locator; extensions/mimes registered for
ALL breadth formats (m4b/m4a/mp3/flac — deliberate per the DOC/LIT
doctrine, m4b scans richly first); classifyFormatGroup 'audiobook'
case (gotcha 39 recomputes on rescan); Go mime table extended at boot
so media elements accept the streams; ffmpeg/ffprobe in the image
(8.1.2 — also the xHE-AAC identification tripwire).

Phase 2 (ingest): sidecar-first (Libation/ABS metadata.json —
narrators/ASIN/curated chapters), ffprobe fallback/filler (duration,
bitrate, codec/profile, embedded chapters). Fixed three real
parser brittlenesses the Libation sidecar exposed: series accepts
string OR array-of-objects, publishedYear accepts number OR string,
ffprobe chapter timings accept number OR string (flexFloat). Folder-
structure fallback now runs on the UPDATE path too (rescans were
clearing sidecar-absent series/author); audio facts re-derive on
every rescan (gotcha 39).

Phase 3 (playback + sync): GET /api/media-items/:id/chapters (the
format-abstraction list); streaming rides the existing cookie-authed
Range /uploads path; PUT progress carries audio_offset_seconds +
elapsed_seconds (honest wall-clock playing time) — the reading-
history capture prefers player-reported elapsed over the inter-push
delta, same 2h ceiling; reading_mode='audio' marks the row.

Phase 4 (web player): dedicated audio reader page (foliate not
involved) — cover, chapter title, whole-book scrubber, skip ± (chips
1/5/10/15/30s, default 10s), speed (0.75×–2×), chapter list with
jump-to, Media Session lockscreen/notification transport, periodic
playing-only progress pushes, position restore on open.

Verified live: ingest of the Libation sample (Gardens of the Moon —
title/author/series/cover/date from sidecar+folders, 34 chapters,
26h duration, aac/LC); chapters endpoint; the reader route serving
the player; playback with position restore (0:57 round-trip);
progress rows in audio mode; wall-clock session rows in
reading_history.

internal/services/series_service_test.go

@@ -83,36 +83,36 @@ func TestContinueSeriesRowToMediaItems_AllFieldsMapped(t *testing.T) {
 	libUUID := uuid.New()
 
 	row := database.GetContinueSeriesItemsRow{
-		ID:                 pgtype.UUID{Bytes: itemUUID, Valid: true},
-		LibraryID:          pgtype.UUID{Bytes: libUUID, Valid: true},
-		Title:              "Full Book",
-		Author:             pgtype.Text{String: "Author", Valid: true},
-		Isbn:               pgtype.Text{String: "ISBN", Valid: true},
-		Description:        pgtype.Text{String: "Desc", Valid: true},
-		FilePath:           "/book.epub",
-		FileSize:           pgtype.Int8{Int64: 2048, Valid: true},
-		MimeType:           pgtype.Text{String: "epub", Valid: true},
-		CoverImagePath:     pgtype.Text{String: "/cover.jpg", Valid: true},
-		Series:             pgtype.Text{String: "Series", Valid: true},
-		SeriesNumber:       pgtype.Int4{Int32: 1, Valid: true},
-		Tags:               []string{"tag1"},
-		Asin:               pgtype.Text{String: "ASIN", Valid: true},
-		Publisher:          pgtype.Text{String: "Pub", Valid: true},
-		Language:           pgtype.Text{String: "en", Valid: true},
-		Edition:            pgtype.Text{String: "1st", Valid: true},
-		Genre:              pgtype.Text{String: "Fiction", Valid: true},
-		FormatGroup:        "epub",
-		FormatMimetype:     pgtype.Text{String: "application/epub+zip", Valid: true},
-		IsReflowable:       pgtype.Bool{Bool: true, Valid: true},
-		HasFixedLayout:     pgtype.Bool{Bool: false, Valid: true},
-		TotalCharacters:    pgtype.Int8{Int64: 500000, Valid: true},
-		ChapterCount:       pgtype.Int4{Int32: 20, Valid: true},
-		MangaType:          pgtype.Text{String: "manga", Valid: true},
-		ReadingDirection:   pgtype.Text{String: "rtl", Valid: true},
-		SeriesCount:        pgtype.Int4{Int32: 10, Valid: true},
-		Volume:             pgtype.Int4{Int32: 1, Valid: true},
-		LibraryTypeName:    pgtype.Text{String: "ebooks", Valid: true},
-		FileSha256:         pgtype.Text{String: "abc123", Valid: true},
+		ID:               pgtype.UUID{Bytes: itemUUID, Valid: true},
+		LibraryID:        pgtype.UUID{Bytes: libUUID, Valid: true},
+		Title:            "Full Book",
+		Author:           pgtype.Text{String: "Author", Valid: true},
+		Isbn:             pgtype.Text{String: "ISBN", Valid: true},
+		Description:      pgtype.Text{String: "Desc", Valid: true},
+		FilePath:         "/book.epub",
+		FileSize:         pgtype.Int8{Int64: 2048, Valid: true},
+		MimeType:         pgtype.Text{String: "epub", Valid: true},
+		CoverImagePath:   pgtype.Text{String: "/cover.jpg", Valid: true},
+		Series:           pgtype.Text{String: "Series", Valid: true},
+		SeriesNumber:     pgtype.Int4{Int32: 1, Valid: true},
+		Tags:             []string{"tag1"},
+		Asin:             pgtype.Text{String: "ASIN", Valid: true},
+		Publisher:        pgtype.Text{String: "Pub", Valid: true},
+		Language:         pgtype.Text{String: "en", Valid: true},
+		Edition:          pgtype.Text{String: "1st", Valid: true},
+		Genre:            pgtype.Text{String: "Fiction", Valid: true},
+		FormatGroup:      "epub",
+		FormatMimetype:   pgtype.Text{String: "application/epub+zip", Valid: true},
+		IsReflowable:     pgtype.Bool{Bool: true, Valid: true},
+		HasFixedLayout:   pgtype.Bool{Bool: false, Valid: true},
+		TotalCharacters:  pgtype.Int8{Int64: 500000, Valid: true},
+		ChapterCount:     pgtype.Int4{Int32: 20, Valid: true},
+		MangaType:        pgtype.Text{String: "manga", Valid: true},
+		ReadingDirection: pgtype.Text{String: "rtl", Valid: true},
+		SeriesCount:      pgtype.Int4{Int32: 10, Valid: true},
+		Volume:           pgtype.Int4{Int32: 1, Valid: true},
+		LibraryTypeName:  pgtype.Text{String: "ebooks", Valid: true},
+		FileSha256:       pgtype.Text{String: "abc123", Valid: true},
 	}
 
 	result := continueSeriesRowToMediaItems(row)