feat: let the viewer pick the audio track

The streaming path mapped 0:a:0 unconditionally, so a dubbed film played in
whichever language was muxed first and the others were unreachable. The node
now enumerates the tracks in stream_init and honours audio_track in
stream_req; switching is the seek path, since one ffmpeg carries one track.

MNP 3.2, additive: the player draws its selector from the node's own list and
never from a version number, so an older node is never asked for a track it
would ignore. MNP_MIN_SUPPORTED does not move.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

10 files changed, 20 insertions, 0 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js
index cb92b18..806fa38 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/de.js
@@ -249,6 +249,8 @@ export default {
   'video.buffering': 'Wird gepuffert …',
   'video.resumed_at': "Fortgesetzt bei {time}",
   'video.from_start': "Von vorn beginnen",
+  'video.audio_track': 'Tonspur',
+  'video.audio_track_n': 'Spur {n}',
   'video.close': 'Schließen (Esc)',
   'preview.pdf_fallback': 'Dieser Browser zeigt das PDF nicht direkt an. Laden Sie es '
     + 'stattdessen herunter — entschlüsselt wurde es ohnehin hier.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js
index 3b84c3c..92114c9 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/en.js
@@ -248,6 +248,8 @@ export default {
   'video.buffering': 'Buffering...',
   'video.resumed_at': "Resumed at {time}",
   'video.from_start': "Start from the beginning",
+  'video.audio_track': 'Audio track',
+  'video.audio_track_n': 'Track {n}',
   'video.close': 'Close (Esc)',
   'preview.pdf_fallback': 'This browser will not display the PDF inline. Download it instead — it was decrypted here either way.',
   'preview.too_large': 'This file is {size}, more than this page can hold in memory ({limit}). Download it instead — a download is written straight to disk.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js
index 145f464..d9b8f63 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/es.js
@@ -247,6 +247,8 @@ export default {
   'video.buffering': 'Almacenando en búfer...',
   'video.resumed_at': "Reanudado en {time}",
   'video.from_start': "Empezar desde el principio",
+  'video.audio_track': 'Pista de audio',
+  'video.audio_track_n': 'Pista {n}',
   'video.close': 'Cerrar (Esc)',
   'preview.pdf_fallback': 'Este navegador no mostrará el PDF integrado. Descárguelo '
     + 'en su lugar — en cualquier caso se descifró aquí.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js
index a4f32de..d507d28 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/fr.js
@@ -248,6 +248,8 @@ export default {
   'video.buffering': 'Mise en mémoire tampon...',
   'video.resumed_at': "Reprise à {time}",
   'video.from_start': "Reprendre depuis le début",
+  'video.audio_track': 'Piste audio',
+  'video.audio_track_n': 'Piste {n}',
   'video.close': 'Fermer (Échap)',
   'preview.pdf_fallback': 'Ce navigateur n’affichera pas le PDF directement. '
     + 'Téléchargez-le plutôt — il a été déchiffré ici dans les deux cas.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js
index 1da0793..b6c68dd 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/it.js
@@ -248,6 +248,8 @@ export default {
   'video.buffering': 'Buffering in corso...',
   'video.resumed_at': "Ripreso da {time}",
   'video.from_start': "Riparti dall'inizio",
+  'video.audio_track': 'Traccia audio',
+  'video.audio_track_n': 'Traccia {n}',
   'video.close': 'Chiudi (Esc)',
   'preview.pdf_fallback': 'Questo browser non mostrerà il PDF nella pagina. Lo scarichi '
     + 'invece — in ogni caso è stato decifrato qui.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js
index 971ecb2..99e2e1f 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/ja.js
@@ -245,6 +245,8 @@ export default {
   'video.buffering': 'バッファリング中…',
   'video.resumed_at': "{time} から再開しました",
   'video.from_start': "最初から再生する",
+  'video.audio_track': '音声トラック',
+  'video.audio_track_n': 'トラック {n}',
   'video.close': '閉じる（Esc）',
   'preview.pdf_fallback': 'このブラウザーはページ内に PDF を表示しません。'
     + 'ダウンロードしてご覧ください。いずれにせよ復号はここで行われています。',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js
index dae63d2..269fa70 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/nl.js
@@ -249,6 +249,8 @@ export default {
   'video.buffering': 'Bezig met bufferen...',
   'video.resumed_at': "Hervat op {time}",
   'video.from_start': "Vanaf het begin afspelen",
+  'video.audio_track': 'Audiospoor',
+  'video.audio_track_n': 'Spoor {n}',
   'video.close': 'Sluiten (Esc)',
   'preview.pdf_fallback': 'Deze browser toont de PDF niet in de pagina zelf. Download '
     + 'hem in plaats daarvan — ontsleuteld werd hij hoe dan ook hier.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js
index 639d518..363296c 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/pl.js
@@ -254,6 +254,8 @@ export default {
   'video.buffering': 'Buforowanie...',
   'video.resumed_at': "Wznowiono od {time}",
   'video.from_start': "Odtwórz od początku",
+  'video.audio_track': 'Ścieżka dźwiękowa',
+  'video.audio_track_n': 'Ścieżka {n}',
   'video.close': 'Zamknij (Esc)',
   'preview.pdf_fallback': 'Ta przeglądarka nie wyświetli pliku PDF na stronie. Proszę '
     + 'go pobrać — i tak został odszyfrowany tutaj.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js
index 371b84f..2a90956 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/pt-BR.js
@@ -249,6 +249,8 @@ export default {
   'video.buffering': 'Armazenando em buffer...',
   'video.resumed_at': "Retomado em {time}",
   'video.from_start': "Começar do início",
+  'video.audio_track': 'Faixa de áudio',
+  'video.audio_track_n': 'Faixa {n}',
   'video.close': 'Fechar (Esc)',
   'preview.pdf_fallback': 'Este navegador não exibirá o PDF na própria página. Baixe '
     + 'o arquivo — de todo modo ele foi descriptografado aqui.',
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js b/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
index 96ba4fe..e3aa440 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/locales/zh-CN.js
@@ -243,6 +243,8 @@ export default {
   'video.buffering': '正在缓冲…',
   'video.resumed_at': "已从 {time} 继续播放",
   'video.from_start': "从头开始播放",
+  'video.audio_track': '音轨',
+  'video.audio_track_n': '音轨 {n}',
   'video.close': '关闭（Esc）',
   'preview.pdf_fallback': '此浏览器不会在页面内显示该 PDF。请改为下载——无论如何它都已在本地解密。',
   'preview.too_large': '该文件为 {size}，超出本页面可在内存中保存的上限（{limit}）。请改为下载——下载会直接写入磁盘。',