The checks engine, the path and the cards: me-web? 0.1 reads the connection

MeWeb.Core runs seven checks concurrently and reports each as it settles:
online or behind a login page, this connection, the public IPv4 and IPv6
seen from v4./v6.meweb, the provider from a built-in map, the router
(UPnP IGD, NAT-PMP and PCP, read-only), address sharing (router WAN
against the echo, TTL hops only as a hint), and the history kept on the
device. The app draws the path from this device to the internet and lights
it node by node, with a card per check and a sheet listing every host it
contacts.

The provider map is iptoasn's table compressed to 2.1 MB by
tools/knowledge.cs and built before every app release; eleven Italian
provider profiles carry each fact with who said it, the source and the
month. The server gains a download page (en, it) and /download/{platform}
from the latest Gitea release.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

src/MeWeb.App/Services/Languages.cs

@@ -30,7 +30,7 @@ public static class Languages
       var found = Find(current.Name);
       if (found is not null) return found;
     }
-    return Fallback;
+    return Find(Fallback.Code) ?? Fallback;
   }
 
   static List<Language> Load()

src/MeWeb.App/Services/Localizer.cs

@@ -27,7 +27,17 @@ public sealed class Localizer : INotifyPropertyChanged
 
   public string this[string key] => current.GetValueOrDefault(key) ?? english.GetValueOrDefault(key) ?? key;
 
-  public string Format(string key, params object[] args) => string.Format(Culture, this[key], args);
+  public string Format(string key, params object[] args)
+  {
+    try
+    {
+      return string.Format(Culture, this[key], args);
+    }
+    catch (FormatException)
+    {
+      return this[key];
+    }
+  }
 
   public void SetLanguage(Language language)
   {

src/MeWeb.App/Services/ServerClient.cs

@@ -1,33 +0,0 @@
-using System.Net.Http.Json;
-
-using MeWeb.Shared;
-
-namespace MeWeb.App.Services;
-
-public enum Reachability
-{
-  Unknown,
-  Online,
-  Offline,
-}
-
-public class ServerClient(IHttpClientFactory factory)
-{
-  public const string Name = "server";
-
-  public async Task<(Reachability State, ViewInfo Info)> Probe(CancellationToken ct)
-  {
-    try
-    {
-      var http = factory.CreateClient(Name);
-      using var timeout = CancellationTokenSource.CreateLinkedTokenSource(ct);
-      timeout.CancelAfter(TimeSpan.FromSeconds(6));
-      var info = await http.GetFromJsonAsync(Endpoints.Server.GET_Info, MeWebJsonContext.Default.ViewInfo, timeout.Token);
-      return (Reachability.Online, info);
-    }
-    catch (Exception ex) when (ex is HttpRequestException or TaskCanceledException && !ct.IsCancellationRequested)
-    {
-      return (Reachability.Offline, null);
-    }
-  }
-}

src/MeWeb.App/Services/Texts.cs

@@ -0,0 +1,52 @@
+using System.Globalization;
+
+using MeWeb.Core.Checks;
+
+namespace MeWeb.App.Services;
+
+public static class Texts
+{
+  public static string Summary(Finding finding) => finding?.Summary is null ? "" : Localizer.Instance.Format(finding.Summary, finding.Args.Select(Argument).ToArray());
+
+  public static string Value(Fact fact)
+  {
+    if (fact.Text is not null) return Isolate(fact.Text);
+    if (fact.Key is null) return fact.Date is null ? "" : Date(fact.Date);
+    var args = fact.Amount is null ? fact.Args.Select(Argument).ToArray() : new object[] { Money(fact.Amount.Value, fact.Currency) };
+    return Localizer.Instance.Format(fact.Key, args);
+  }
+
+  public static string Source(Fact fact)
+  {
+    var parts = new List<string>();
+    if (fact.Basis is not null) parts.Add(Localizer.Instance[fact.Basis]);
+    if (fact.Date is not null && fact.Key is not null) parts.Add(Date(fact.Date));
+    return string.Join(", ", parts);
+  }
+
+  public static string Money(decimal amount, string currency)
+  {
+    var format = (NumberFormatInfo)Localizer.Instance.Culture.NumberFormat.Clone();
+    format.CurrencySymbol = currency switch
+    {
+      "EUR" => "€",
+      "USD" => "$",
+      "GBP" => "£",
+      _ => currency ?? "",
+    };
+    return amount.ToString("C2", format);
+  }
+
+  public static string Date(string text)
+  {
+    var culture = Localizer.Instance.Culture;
+    if (DateTime.TryParseExact(text, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out var day)) return day.ToString("d", culture);
+    if (DateTime.TryParseExact(text, "yyyy-MM", CultureInfo.InvariantCulture, DateTimeStyles.None, out var month)) return month.ToString("Y", culture);
+    return text;
+  }
+
+  public static string Isolate(string text) => string.IsNullOrEmpty(text) ? text : $"\u2068{text}\u2069";
+
+  static object Argument(string text) =>
+      DateTime.TryParseExact(text, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out var day) ? day.ToString("d", Localizer.Instance.Culture) : text;
+}