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/DeviceScanPage.xaml

@@ -0,0 +1,44 @@
+<?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"
+             xmlns:ble="clr-namespace:FieldLogger.Services.Ble"
+             x:Class="FieldLogger.Views.DeviceScanPage"
+             x:DataType="vm:DeviceScanViewModel"
+             Title="{Binding Title}">
+    <Grid RowDefinitions="Auto,Auto,*" Padding="16" RowSpacing="12">
+
+        <Label Grid.Row="0" Text="{Binding Hint}" FontSize="13" TextColor="Gray" />
+
+        <HorizontalStackLayout Grid.Row="1" Spacing="12">
+            <Button Text="{Binding ScanButtonText}" Command="{Binding ScanCommand}" IsEnabled="{Binding IsScanning, Converter={StaticResource InvertBool}}" />
+            <ActivityIndicator IsRunning="{Binding IsScanning}" VerticalOptions="Center" />
+        </HorizontalStackLayout>
+
+        <CollectionView Grid.Row="2" ItemsSource="{Binding Devices}">
+            <CollectionView.EmptyView>
+                <Label Text="No devices found yet." TextColor="Gray" Margin="8" />
+            </CollectionView.EmptyView>
+            <CollectionView.ItemTemplate>
+                <DataTemplate x:DataType="ble:DiscoveredDevice">
+                    <Border StrokeThickness="0" Background="{AppThemeBinding Light=#F2F2F7, Dark=#1C1C1E}"
+                            StrokeShape="RoundRectangle 10" Padding="12" Margin="0,4">
+                        <Border.GestureRecognizers>
+                            <TapGestureRecognizer
+                                Command="{Binding SelectCommand, Source={RelativeSource AncestorType={x:Type vm:DeviceScanViewModel}}}"
+                                CommandParameter="{Binding .}" />
+                        </Border.GestureRecognizers>
+                        <Grid ColumnDefinitions="*,Auto">
+                            <VerticalStackLayout Spacing="2">
+                                <Label Text="{Binding Name}" FontAttributes="Bold" />
+                                <Label Text="{Binding Id}" FontSize="11" TextColor="Gray" />
+                            </VerticalStackLayout>
+                            <Label Grid.Column="1" VerticalOptions="Center" FontSize="12" TextColor="Gray"
+                                   Text="{Binding Rssi, StringFormat='{0} dBm'}" />
+                        </Grid>
+                    </Border>
+                </DataTemplate>
+            </CollectionView.ItemTemplate>
+        </CollectionView>
+    </Grid>
+</ContentPage>