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.Core/Checks/Finding.cs

@@ -0,0 +1,70 @@
+namespace MeWeb.Core.Checks;
+
+public enum CheckId
+{
+  Online,
+  Connection,
+  Addresses,
+  Provider,
+  Router,
+  Nat,
+  History,
+}
+
+public enum Outcome
+{
+  Waiting,
+  Running,
+  Good,
+  Caution,
+  Bad,
+  Unknown,
+  Info,
+}
+
+public enum NatKind
+{
+  Unknown,
+  Direct,
+  HomeRouter,
+  DoubleNat,
+  Shared,
+  Translated,
+  NoIpv4,
+}
+
+public class Fact
+{
+  public string Label { get; set; }
+  public string Text { get; set; }
+  public string Key { get; set; }
+  public List<string> Args { get; set; } = [];
+  public decimal? Amount { get; set; }
+  public string Currency { get; set; }
+  public string Link { get; set; }
+  public string Basis { get; set; }
+  public string Date { get; set; }
+}
+
+public class Finding
+{
+  public CheckId Id { get; set; }
+  public Outcome Outcome { get; set; }
+  public string Summary { get; set; }
+  public List<string> Args { get; set; } = [];
+  public List<Fact> Facts { get; set; } = [];
+
+  public static Finding Running(CheckId id) => new() { Id = id, Outcome = Outcome.Running };
+
+  public Finding With(string label, string text)
+  {
+    if (!string.IsNullOrEmpty(text)) Facts.Add(new Fact { Label = label, Text = text });
+    return this;
+  }
+
+  public Finding WithKey(string label, string key, params string[] args)
+  {
+    Facts.Add(new Fact { Label = label, Key = key, Args = [.. args] });
+    return this;
+  }
+}