feat(client): fetch the media apps, the player, settings and search on first use

apps.js registers Videos, Music, Photos and every settings pane through
lazy.js; the group page does the same for the video player and the
settings panel, and the shell for the search page. The first download
goes from 49 modules / 386 KB gzip to 37 / 289 KB; opening Music now
fetches music-app.js and media-tiles.js and nothing of Videos.
test_first_load_is_lean holds the eager graph; test_spa_imports checks
that every on-demand load names an export that exists.

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

1 files changed, 14 insertions, 9 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/apps.js b/packages/meshbay-hub/src/meshbay_hub/static/apps.js
index eec2158..8ae4db4 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/apps.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/apps.js
@@ -1,14 +1,19 @@
 import { ChatPanel } from './chat-app.js';
 import { FilesPanel } from './files-app.js';
-import { VideoApp } from './video-app.js';
-import { MusicApp } from './music-app.js';
-import { PhotosApp } from './photos-app.js';
-import { ChatSettings } from './chat-app-settings.js';
-import { VideoSettings } from './video-app-settings.js';
-import { MusicSettings } from './music-app-settings.js';
-import { PhotoSettings } from './photos-app-settings.js';
-import { HelloWorldApp } from './helloworld-app.js';
-import { HelloWorldSettings } from './helloworld-app-settings.js';
+import { lazy } from './lazy.js';
+
+// Chat and Files open with the group; every other app, and every settings
+// pane, is fetched the first time it is shown (lazy.js) — a member who only
+// chats never downloads the Videos app.
+const VideoApp = lazy(() => import('./video-app.js'), 'VideoApp');
+const MusicApp = lazy(() => import('./music-app.js'), 'MusicApp');
+const PhotosApp = lazy(() => import('./photos-app.js'), 'PhotosApp');
+const ChatSettings = lazy(() => import('./chat-app-settings.js'), 'ChatSettings');
+const VideoSettings = lazy(() => import('./video-app-settings.js'), 'VideoSettings');
+const MusicSettings = lazy(() => import('./music-app-settings.js'), 'MusicSettings');
+const PhotoSettings = lazy(() => import('./photos-app-settings.js'), 'PhotoSettings');
+const HelloWorldApp = lazy(() => import('./helloworld-app.js'), 'HelloWorldApp');
+const HelloWorldSettings = lazy(() => import('./helloworld-app-settings.js'), 'HelloWorldSettings');
 
 /**
  * Whether apps marked `dev` are shown. Opt in once with `?dev=1`, off with