feat(cast): photos on the TV, and a television chosen once for the session

A cast button in Videos' toolbar, at the top of Photos, in an album's bar and
in the lightbox, in a group and in Search alike. A television chosen there is
kept for the session: a film opened plays on it with the player as its remote
from the start, and a photo opened in the lightbox is shown on it, scaled to
1920x1080, upright, as JPEG. The lightbox gains a slideshow.

The relay serves one photo at /image behind the stream's token, on the desktop
and on Android; the shell, not the page, decides that the receiver loads it as
a picture.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/CLAUDE.md b/CLAUDE.md
index 4f39e36..32ffc25 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -921,6 +921,16 @@ do. Read them before writing anything that touches the same mechanism.
   machine could. The receiver was half-crashed; a power cycle fixed it. A
   machine that reaches the receiver proves nothing about the phone
 
+- **The default media receiver will not start a stream that arrives at real
+  time.** Casting the interface as live video, it stayed on BUFFERING until the
+  end of the file — with or without audio, at any bitrate. It started only with
+  an audio track *and* the first seconds delivered faster than real time, and
+  then kept that lead as five seconds of latency. A film meets both conditions
+  by construction, which is why films cast. Before that was found, a receiver in
+  a bad state had made single runs contradict each other for an hour: power-cycle
+  it, prove a real film casts, repeat every case, and run a known reference
+  first and last
+
 **Corrections that used to live here** — `punch_nat()` is not a traversal stack,
 the node keystore's Argon2id parameters, what group chat actually uses, and what
 is sealed on the wire — are now design statements in `docs/MESHBAY_DESIGN.md`
@@ -1023,6 +1033,7 @@ here are kept only where they are a rule about *editing* the code.
 | Where the hub is | `platform.js` — `hubBase()` | **the only file allowed to decide this** (§8.3) |
 | Downloads, decrypt pipeline | `file-utils.js`, `downloads.js`, `sw.js` | §8.5 |
 | Video player | `video-player.js` — `pump()` is the only place credit is granted | §8.5 |
+| The television a session casts to, photos on it | `cast-session.js` | §11.4 |
 | Transfers widget | `transfers.js` | §5.5 |
 | Cross-group merge | `source-merge.js`, `group-name.js` | §9.11 |
 | Node page | `node-page.js` | §6.7 |
@@ -1057,6 +1068,7 @@ when `ANDROID_HOME` is set (`test_android_shell.py`).
 | An invitation answered on the home page (accept, decline), in both engines | `packages/meshbay-hub/tests/harness/invitation_probe.py` |
 | A group owner's invited list and host approvals, in both engines | `packages/meshbay-hub/tests/harness/group_hosts_probe.py` |
 | A show's modal and the player, walked episode to episode | `packages/meshbay-hub/tests/harness/video_series_probe.py` |
+| A television chosen once, then photos and a film sent to it, in both engines | `packages/meshbay-hub/tests/harness/cast_session_probe.py` |
 | A lazily loaded view whose module answers 404 (a tab older than the deploy) | `packages/meshbay-hub/tests/harness/lazy_failure_probe.py` |
 
 ## meshbay.org server (target state)