ARCH-2b: add frontend (Vite) as Aspire resource with LAN wiring

- AppHost: AddViteApp(frontend) via Aspire.Hosting.JavaScript 13.4.2,
  WithReference(webapi)+WaitFor, inject VITE_API_BASE_URL=http://<lan-ip>:5179
  at launch (computed from the active physical adapter, follows DHCP)
- Pin proxyless ports: webapi http=5179 (matches SPA default), vite=5173,
  both bind 0.0.0.0 for LAN reachability
- vite.config: server.host=true so the dev server is LAN-visible

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

GerbilManager.AppHost/AppHost.cs

@@ -1,3 +1,7 @@
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Net.Sockets;
+
 var builder = DistributedApplication.CreateBuilder(args);
 
 var postgres = builder.AddPostgres("postgres")
@@ -5,8 +9,65 @@ var postgres = builder.AddPostgres("postgres")
 
 var gerbilDb = postgres.AddDatabase("gerbilmanager");
 
-builder.AddProject<Projects.GerbilManagerWebAPI>("webapi")
+// Stable, LAN-facing HTTP port for the API (matches the SPA's default base URL).
+const int ApiHttpPort = 5179;
+
+var webapi = builder.AddProject<Projects.GerbilManagerWebAPI>("webapi")
     .WithReference(gerbilDb)
-    .WaitFor(gerbilDb);
+    .WaitFor(gerbilDb)
+    // Pin the port so the phone-facing URL doesn't change between launches.
+    // Proxyless so the app binds the port directly — Program.cs then widens the
+    // host to 0.0.0.0 for LAN access (the DCP proxy binds localhost only).
+    .WithEndpoint("http", e => { e.Port = ApiHttpPort; e.IsProxied = false; }, createIfNotExists: false)
+    .WithExternalHttpEndpoints();
+
+// The machine's LAN IP — the SPA runs in the phone's browser, so it must reach
+// the API at this address, not "localhost" (which would be the phone itself).
+var lanIp = GetLanIpAddress();
+
+builder.AddViteApp("frontend", "../gerbil-manager-web")
+    .WithReference(webapi)
+    .WaitFor(webapi)
+    // Pin a stable port for the phone bookmark (Vite default 5173). Proxyless so
+    // the Vite dev server binds the port directly; vite.config host:true makes it
+    // bind 0.0.0.0 for LAN access.
+    .WithEndpoint("http", e => { e.Port = 5173; e.IsProxied = false; }, createIfNotExists: false)
+    .WithExternalHttpEndpoints()
+    .WithEnvironment(context =>
+    {
+        // VITE_API_BASE_URL is read by the Vite dev server at launch (see
+        // src/api/client.ts). Point it at the API's LAN-reachable URL.
+        context.EnvironmentVariables["VITE_API_BASE_URL"] = $"http://{lanIp}:{ApiHttpPort}";
+    });
 
 builder.Build().Run();
+
+// Picks the IPv4 address of the active physical LAN adapter (Wi-Fi/Ethernet),
+// skipping loopback and virtual adapters (WSL/Hyper-V). Recomputed each launch
+// so it follows DHCP changes.
+static string GetLanIpAddress()
+{
+    var candidates = NetworkInterface.GetAllNetworkInterfaces()
+        .Where(ni => ni.OperationalStatus == OperationalStatus.Up)
+        .Where(ni => ni.NetworkInterfaceType is NetworkInterfaceType.Wireless80211
+                                              or NetworkInterfaceType.Ethernet)
+        .Where(ni => !ni.Description.Contains("Hyper-V", StringComparison.OrdinalIgnoreCase)
+                  && !ni.Description.Contains("Virtual", StringComparison.OrdinalIgnoreCase)
+                  && !ni.Name.Contains("WSL", StringComparison.OrdinalIgnoreCase)
+                  && !ni.Name.Contains("vEthernet", StringComparison.OrdinalIgnoreCase))
+        // Prefer adapters that have a default gateway (i.e. a real network path).
+        .OrderByDescending(ni => ni.GetIPProperties().GatewayAddresses.Count > 0);
+
+    foreach (var ni in candidates)
+    {
+        var ip = ni.GetIPProperties().UnicastAddresses
+            .FirstOrDefault(a => a.Address.AddressFamily == AddressFamily.InterNetwork
+                              && !IPAddress.IsLoopback(a.Address));
+        if (ip is not null)
+        {
+            return ip.Address.ToString();
+        }
+    }
+
+    return "localhost";
+}

GerbilManager.AppHost/GerbilManager.AppHost.csproj

@@ -9,6 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Aspire.Hosting.JavaScript" Version="13.4.2" />
     <PackageReference Include="Aspire.Hosting.PostgreSQL" Version="13.4.2" />
   </ItemGroup>
 

gerbil-manager-web/vite.config.ts

@@ -4,4 +4,10 @@ import react from '@vitejs/plugin-react'
 // https://vite.dev/config/
 export default defineConfig({
   plugins: [react()],
+  server: {
+    // Bind on all interfaces so the dev server is reachable from other devices
+    // on the LAN (phone/laptop) when launched via .NET Aspire. Aspire assigns
+    // the port; this only widens the host from localhost to 0.0.0.0.
+    host: true,
+  },
 })