me-web? 0.2: the test from outside, calls and games, mail, and what you can host

Phases two and three ship together, because their code grew in the same
files. With consent the app asks the router to open 80, 443 and a high
port for ten minutes (UPnP, NAT-PMP or PCP), and the server, holding a
single-use ticket bound to the caller's own address, connects back and
must get an HMAC only the app can give; the mappings are removed after the
run and remembered until then, so a crash cannot leave one open. Hairpin
is tried from inside. Two STUN servers, the outside one first, tell easy
from hard NAT.

Mail gets port 25 to Gmail and Outlook, the reverse name and five
blocklists through the user's own resolver, network-wide UCEPROTECT
listings counted as a caution. DNS, speed against the server (four at a
time, twelve an hour per address) and the device follow, and six uses
(website, home from outside, files, game server, fediverse, mail) close
the run as possible, possible with a named workaround, or can't tell.

Findings can be shared after reading the exact JSON: a file per submission
under the unit's state directory, ten a day per address, deletable by the
token the app keeps, swept after twelve months; /privacy says all of it in
English and Italian. QR codes lead to the downloads. Every language carries
every string.

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

src/MeWeb.Core/Checks/SharePayload.cs

@@ -0,0 +1,30 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace MeWeb.Core.Checks;
+
+public class SharePayload
+{
+  public string App { get; set; }
+  public string Platform { get; set; }
+  public string Language { get; set; }
+  public DateTimeOffset CheckedAt { get; set; }
+  public List<Finding> Findings { get; set; } = [];
+
+  public static SharePayload From(RunReport run, string app, string platform, string language) => new()
+  {
+    App = app,
+    Platform = platform,
+    Language = language,
+    CheckedAt = run.StartedAt,
+    Findings = [.. run.Findings.OrderBy(f => f.Id)],
+  };
+
+  public string ToJson() => JsonSerializer.Serialize(this, ShareJsonContext.Default.SharePayload);
+}
+
+[JsonSourceGenerationOptions(JsonSerializerDefaults.Web, WriteIndented = true, UseStringEnumConverter = true, DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)]
+[JsonSerializable(typeof(SharePayload))]
+public partial class ShareJsonContext : JsonSerializerContext
+{
+}