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/Views/MapPage.xaml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:vm="clr-namespace:FieldLogger.ViewModels"
+             x:Class="FieldLogger.Views.MapPage"
+             x:DataType="vm:MapViewModel"
+             Title="Map">
+    <Grid RowDefinitions="Auto,*">
+        <Label Grid.Row="0" Text="{Binding StatusText}" FontSize="12" TextColor="Gray" Padding="12,6" />
+        <!-- Populated in code-behind: native Map control on iOS/Android/macOS, Google Maps WebView on Windows. -->
+        <ContentView Grid.Row="1" x:Name="MapHost" />
+    </Grid>
+</ContentPage>