Revive yaris-obd: USB OBD adapter, real GPS/GNSS, offline map, hotspot, SQLite logging, dashcam retrieval

Squashed rewrite of the project revival work (replaces prior history on this
branch to remove personal data that had been accidentally committed - real
LAN IP, GPS coordinates, home WiFi SSID, and phone model). See PLAN.md for
full phase-by-phase details. Summary:

- Phase 2: adapt app_obd.py for a USB OBD-II adapter (was Bluetooth-only),
  auto-detect /dev/ttyUSB*, fix several pre-existing crash bugs.
- Phase 3/4: make the web UI work fully offline (vendored Socket.IO/Leaflet/
  Chart.js/FontAwesome, offline map tile downloader script, live GPS marker
  tracking fix).
- Phase 5: systemd deployment/autostart on the Pi.
- Phase 6: WiFi hotspot mode via NetworkManager (auto-switch between home
  WiFi and a local AP for in-car web UI access), mDNS hostname + port 80
  redirect so the UI is reachable at a plain hostname with no port number.
- Phase 7: fix app_db.py/app_sql.py bugs, wire up local SQLite trip logging.
- Phase 8: brand-agnostic USB dashcam file retrieval (lsblk transport-based
  detection, works with any dashcam brand/folder layout).
- Rewritten readme.md with a proper project overview.

Co-authored-by: Copilot <[email protected]>

templates/index.html

@@ -7,9 +7,8 @@
     <title>Dashboard - yaris vroom vroom de course</title>
     <link rel="stylesheet" href="{{ url_for('static', filename='bootstrap/css/bootstrap.min.css') }}">
     <link rel="stylesheet" href="{{ url_for('static', filename='yaris.css') }}">
-    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Nunito:200,200i,300,300i,400,400i,600,600i,700,700i,800,800i,900,900i&amp;display=swap">
-    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.12.0/css/all.css">
-    <link rel="stylesheet" href="https://unpkg.com/[email protected]/dist/leaflet.css" integrity="sha256-p4NxAoJBhIIN+hmNHrzRCf9tD/miZyoHS5obTRR9BMY=" crossorigin=""/>
+    <link rel="stylesheet" href="{{ url_for('static', filename='fonts/fontawesome-all.min.css') }}">
+    <link rel="stylesheet" href="{{ url_for('static', filename='vendor/leaflet/leaflet.css') }}">
 </head>
 
 <body id="page-top">
@@ -180,9 +179,9 @@
             </footer>
         </div><a class="border rounded d-inline scroll-to-top" href="#page-top"><i class="fas fa-angle-up"></i></a>
     </div>
-    <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/4.2.0/socket.io.js"></script>
-    <script src="https://unpkg.com/[email protected]/dist/leaflet.js" integrity="sha256-20nQCchB9co0qIjJZRGuk2/Z9VM+kNiyxNV1lvTlZBo=" crossorigin=""></script>
+    <script src="{{ url_for('static', filename='js/chart.min.js') }}"></script>
+    <script src="{{ url_for('static', filename='vendor/socketio/socket.io.min.js') }}"></script>
+    <script src="{{ url_for('static', filename='vendor/leaflet/leaflet.js') }}"></script>
     <script src="{{ url_for('static', filename='js/yaris.js') }}"></script>
     <script src="{{ url_for('static', filename='bootstrap/js/bootstrap.min.js') }}"></script>
     <script src="{{ url_for('static', filename='js/bs-init.js') }}"></script>