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, 9 insertions, 4 deletions

diff --git a/packages/meshbay-hub/tests/test_session_renewal.py b/packages/meshbay-hub/tests/test_session_renewal.py
index 6c47f7a..a839f1e 100644
--- a/packages/meshbay-hub/tests/test_session_renewal.py
+++ b/packages/meshbay-hub/tests/test_session_renewal.py
@@ -34,7 +34,12 @@ from pathlib import Path
 import pytest
 
 STATIC = Path(__file__).resolve().parents[1] / "src" / "meshbay_hub" / "static"
-APP = STATIC / "app.js"
+APP = STATIC / "hub-client.js"
+# The session/token machinery lives in hub-client.js (APP, above); the group
+# shell's own WebRTC-connect effect that consumes it is in group-page.js; the
+# periodic re-check that catches a backgrounded tab is App() in app.js.
+GROUP_PAGE = STATIC / "group-page.js"
+APP_JS = STATIC / "app.js"
 HARNESS = Path(__file__).parent / "harness" / "session_harness.mjs"
 
 pytestmark = pytest.mark.skipif(
@@ -182,7 +187,7 @@ def test_renewal_happens_before_expiry_not_after():
     assert margin >= 300, (
         f"{margin} s of margin against a one-hour token is thin: a backgrounded "
         "tab has its timers throttled and may not check for minutes")
-    assert "visibilitychange" in src, (
+    assert "visibilitychange" in APP_JS.read_text(), (
         "nothing re-checks when the tab comes back, which is exactly when the "
         "token is most likely to have aged out unnoticed")
 
@@ -203,7 +208,7 @@ def test_renewing_does_not_tear_down_the_webrtc_connection():
     Signing in or out must still re-run it, so the dependency is whether there
     is a token, not which one.
     """
-    src = APP.read_text()
+    src = GROUP_PAGE.read_text()
     i = src.index("means tearing down the WebRTC connection")
     deps = src[i:src.index(");", i)]
     assert "Boolean(token)" in deps, (
@@ -218,7 +223,7 @@ def test_the_connection_signs_its_offer_with_a_live_token():
     It signs the offer relayed through the hub, where an expired one is a 401
     and no connection at all.
     """
-    src = APP.read_text()
+    src = GROUP_PAGE.read_text()
     connect = src[src.index("const connect = async () => {"):]
     connect = connect[:connect.index("\n    };")]
     assert "await ensureFreshToken()" in connect, (