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, 19 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/ops.py b/packages/meshbay-node/src/meshbay_node/ops.py
index daddf17..c9d862a 100644
--- a/packages/meshbay-node/src/meshbay_node/ops.py
+++ b/packages/meshbay-node/src/meshbay_node/ops.py
@@ -711,6 +711,25 @@ async def set_member_upload(state: dict, group_id: str, allowed: bool) -> dict:
     return {"allowed": allowed, "group_id": group_id}
 
 
+# ── Applications ─────────────────────────────────────────────────────────────
+
+async def set_enabled_apps(state: dict, group_id: str, apps: list[str]) -> dict:
+    """
+    Which group "applications" (Chat, Files, ...) are shown to members.
+
+    Same shape as `set_member_upload`: lives on the node (roster.db), takes
+    effect without a restart, and is signed by the operator (webrtc_server.py
+    checks the caller's own admin-authority allow-list before this runs).
+    """
+    roster = _roster(state)
+    ctx = _group_ctx(state, group_id)
+    await roster.set_enabled_apps(group_id, apps,
+                                  set_by=state.get("node_user_id", ""))
+    ctx["enabled_apps"] = apps
+    log.info("Enabled apps for group %s: %s", group_id[:8], ",".join(sorted(apps)))
+    return {"apps": apps, "group_id": group_id}
+
+
 # ── Reload ──────────────────────────────────────────────────────────────────
 
 async def reload_config(state: dict) -> dict: