feat(hub): split the group UI into a pluggable "applications" architecture

GroupPage's 6620-line app.js carried Chat and Files wedged in directly, with
no way to add another group-level app without touching the shell itself. It
is now app.js (routing, non-group pages) plus nine focused files — apps.js
(the registry), chat-app.js, files-app.js, video-player.js, group-page.js
(the shell), group-settings.js, hub-client.js, icon.js and file-utils.js —
with docs/apps.md as the checklist for adding one (Videos/Music/Photos are
sketched there, not built).

Node side gained the matching enablement mechanism, mirroring
member_upload exactly: a roster setting, a signed apps_enabled op enforced
by _has_admin_authority, exposed in the handshake ack. Operators toggle
applications per group from Settings, which also gained a small reorder:
Invite, Pairing, Applications, Shared directories, Uploads, danger zone,
Your devices, Members.

Two bugs surfaced during the split, both missing an import across the new
file boundary and invisible to node --check or a module-load probe since
they only throw when the code path actually runs:

- group-page.js called onRefreshAuth on a stale-token handshake rejection,
  but app.js never imported refreshAccessToken from hub-client.js — so a
  brand new member (including a group's own creator) hit "Not a member of
  this group" and the retry silently failed, throwing before it could
  refresh the token.
- chat-app.js called getLocale() for message timestamps without importing
  it from i18n.js. Opening Chat on a group with real messages threw mid-
  render; uncaught, that appears to wedge Preact's render scheduler, so
  every button on the page stopped responding until reload.

Caught the second class of bug with a proper no-undef audit across all
split files (a temporarily installed ESLint 9, since the system one is too
old to parse this codebase's syntax) rather than trusting grep. 827 tests
pass; 6 new ones cover the apps_enabled policy.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016SF6RKNBKg9qejmoMJ9ybA

1 files changed, 3 insertions, 2 deletions

diff --git a/packages/meshbay-hub/tests/test_video_buffer_ceiling.py b/packages/meshbay-hub/tests/test_video_buffer_ceiling.py
index cf38117..59f97de 100644
--- a/packages/meshbay-hub/tests/test_video_buffer_ceiling.py
+++ b/packages/meshbay-hub/tests/test_video_buffer_ceiling.py
@@ -45,7 +45,7 @@ from pathlib import Path
 import pytest
 
 STATIC = Path(__file__).resolve().parents[1] / "src" / "meshbay_hub" / "static"
-APP = STATIC / "app.js"
+APP = STATIC / "video-player.js"
 NODE_SERVER = (Path(__file__).resolve().parents[2] / "meshbay-node" / "src"
                / "meshbay_node" / "transport" / "webrtc_server.py")
 
@@ -61,7 +61,8 @@ def app():
 
 def _player(app: str) -> str:
     i = app.index("function VideoPlayer(")
-    return app[i:app.index("\nfunction ", i + 1)]
+    nxt = app.find("\nfunction ", i + 1)
+    return app[i:nxt if nxt > 0 else len(app)]
 
 
 # ── The shipped functions, run against a browser that has a ceiling ───────────