Move version display to GET /api/health/version in HealthController

Uses GetApplicationVersion(Assembly.GetExecutingAssembly()) — the same
timestamp-based version already logged at startup and baked into the
assembly via the csproj <Version> property. Removes the minimal-API
/version endpoint from web/Program.cs and reverts the web Dockerfile
APP_VERSION build-arg (no longer needed).

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

web/Dockerfile

@@ -13,8 +13,6 @@ FROM mcr.microsoft.com/dotnet/aspnet:10.0 AS final
 WORKDIR /app
 EXPOSE 8080
 ENV ASPNETCORE_URLS=http://0.0.0.0:8080
-ARG APP_VERSION=1.0.0
-ENV APP_VERSION=${APP_VERSION}
 
 COPY --from=build /app/publish .
 ENTRYPOINT ["dotnet", "web.dll"]

web/Program.cs

@@ -14,9 +14,6 @@ var app = builder.Build();
 
 app.UseMiddleware<SiteModeMiddleware>();
 
-app.MapGet("/version", (IConfiguration config) =>
-    Results.Json(new { version = config["APP_VERSION"] ?? "unknown" }));
-
 // Static site
 app.UseDefaultFiles();
 app.UseStaticFiles();

web/wwwroot/js/main.js

@@ -263,7 +263,7 @@
 
 	$('#year').text(new Date().getFullYear());
 
-	$.getJSON('/version').done(function (data) {
+	$.getJSON('/api/health/version').done(function (data) {
 		if (data && data.version) {
 			$('#app-version').text('v' + data.version);
 		}