feat(apps): OBD2 placeholder rail item (launchpad for the parked OBD2 project)

Adds an OBD2 item to the Apps rail; with no records UI deployed yet it links to
the OBD2 Telemetry project + tasks and the research/wiki page rather than
embedding. Swap to embedView once LubeLogger/Tracktor is up. → 2.1.1.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/app.js

@@ -27,6 +27,7 @@ const VIEWS = {
   terminal:        () => import('./views/terminal.js'),
   timelapse:       () => import('./views/timelapse.js'),
   'ai-usage':      () => import('./views/aiusage.js'),
+  obd2:            () => import('./views/obd2.js'),
   settings:        () => import('./views/settings.js'),
   jobs:            () => import('./views/jobs.js')
 };