Initial commit: FieldLogger MAUI app with Maglink BLE support

Added Maglink RTK GNSS receiver integration with correct BLE UUIDs and device name filtering (ML-* prefix).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

FieldLogger/AppShell.xaml.cs

@@ -0,0 +1,14 @@
+using FieldLogger.Views;
+
+namespace FieldLogger;
+
+public partial class AppShell : Shell
+{
+    public AppShell()
+    {
+        InitializeComponent();
+
+        Routing.RegisterRoute("devicescan", typeof(DeviceScanPage));
+        Routing.RegisterRoute("jobdetail", typeof(JobDetailPage));
+    }
+}