Fix passkey RPID mismatch across environments

Derive ServerDomain and Origin from the incoming HTTP request instead of
appsettings.json, so WebAuthn works on localhost, dev, and production
without any environment-specific configuration. Removed IFido2 from DI
and the Fido2 appsettings block — PasskeyController instantiates Fido2
per-request via BuildFido2().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/PowderCoating.Web/Program.cs

@@ -290,16 +290,9 @@ builder.Services.AddSession(options =>
 // Add memory cache
 builder.Services.AddMemoryCache();
 
-// Register Fido2/WebAuthn for passkey (biometric) login
-builder.Services.AddFido2(options =>
-{
-    options.ServerDomain = builder.Configuration["Fido2:ServerDomain"] ?? "localhost";
-    options.ServerName = builder.Configuration["Fido2:ServerName"] ?? "Powder Coating Logix";
-    var origins = builder.Configuration.GetSection("Fido2:Origins").Get<HashSet<string>>();
-    if (origins?.Count > 0) options.Origins = origins;
-    options.TimestampDriftTolerance = int.Parse(
-        builder.Configuration["Fido2:TimestampDriftTolerance"] ?? "300");
-});
+// Fido2/WebAuthn: no DI registration needed — PasskeyController builds a
+// per-request Fido2 instance from the incoming Host header so the RPID matches
+// automatically on every environment without config changes.
 
 // Configure authorization policies for multi-tenancy
 builder.Services.AddAuthorization(options =>