Videos: know what a clip costs before fetching it; vertical clips only

- What a clip costs is learned up front: the post's imeta (size, dim,
  image) when it says, else one 64 KB ranged request — the total from
  Content-Range, whether ranges are served, whether the MP4's index
  (moov) comes before its data, and the picture size from the track
  header. Up to three at a time; remembered across sessions. It also
  replaces the player-based shape probe the feed ran on every clip.
- Clips over 25 MB (8 MB on 2G/3G, 3 MB with data saver), above 1080p,
  index-last files over 8 MB from servers without ranges, or clips that
  couldn't be measured wait for a tap: a cover saying what they cost
  ("50 MB", "4K"). Settings → Nostr → Videos: Autoplay large videos.
- The pager loads only the clip on screen in full; the next gets its
  opening if within budget; everything else holds nothing. Sizes are
  asked three slides ahead.
- Feed clips fetch nothing until they're about to play (preload none),
  with the post's still as a poster.
- Video grid tiles show a first frame only for small clips that start
  quickly; others show their cost.
- Videos lists only clips known to stand taller than wide; one of unknown
  shape is measured and joins when it qualifies; choosing Videos with none
  known yet opens the pager on the first that turns up.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01ULQZS9MQa6iAsXnrJUD9Du

1 files changed, 5 insertions, 1 deletions

diff --git a/src/i18n.js b/src/i18n.js
index 932b552..e4d2429 100644
--- a/src/i18n.js
+++ b/src/i18n.js
@@ -257,6 +257,10 @@ const STR = {
     close: 'Close',
     playVideo: 'Play',
     videoUnmute: 'Unmute',
+    videoTapToPlay: "Tap to play",
+    videoLargeTitle: "Videos",
+    videoLargeToggle: "Autoplay large videos",
+    videoLargeHelp: "Videos over {mb} MB or above 1080p wait for a tap, so the feed doesn’t eat your data. The limit is lower on a slow or data-saving connection.",
     videoMute: 'Mute',
     openInYouTube: 'Open on YouTube',
     accountsThisOne: 'signed in',
@@ -303,7 +307,7 @@ const STR = {
     mediaImages: "Images",
     mediaVideos: "Videos",
     mediaNoImages: "No pictures in this feed yet.",
-    mediaNoVideos: "No videos in this feed yet.",
+    mediaNoVideos: "No vertical videos in this feed yet.",
     feedRelays: 'Relays',
     feedRelaysFormHelp: 'Read this feed from these relays only. Leave empty for the usual ones.',
     feedAllToggle: 'Every post on these relays (a firehose)',