Pin Aspire AppHost ports/credentials to match docker-compose defaults

Aspire assigned random ports and an auto-generated Postgres password on each
run, so the fixed targets baked into local.runsettings and docker-compose
(localhost:5000/5173/5432, miccheck/password) didn't work when developing via
Aspire instead of docker compose. Pins Postgres user/password/port and the
api/admin HTTP endpoints so either workflow hits the same local addresses.

src/MicCheck.AppHost/AppHost.cs

@@ -1,14 +1,26 @@
 var builder = DistributedApplication.CreateBuilder(args);
 
-var postgres = builder.AddPostgres("postgres").WithDataVolume("miccheck-pgdata").WithPgAdmin();
+// Pinned to match tests/api/MicCheck.Api.Tests.Integration/local.runsettings and
+// src/admin's docker-compose defaults, so those fixed targets work whether the
+// stack is run via `docker compose` or via this AppHost.
+var postgresUser = builder.AddParameter("postgres-username", "miccheck");
+var postgresPassword = builder.AddParameter("postgres-password", "password", secret: true);
+
+var postgres = builder.AddPostgres("postgres", postgresUser, postgresPassword, port: 5432)
+    .WithDataVolume("miccheck-pgdata")
+    .WithPgAdmin();
 
 var miccheckDb = postgres.AddDatabase("miccheck");
 
-var api = builder.AddProject<Projects.MicCheck_Api>("api").WithReference(miccheckDb).WaitFor(miccheckDb);
+var api = builder.AddProject<Projects.MicCheck_Api>("api")
+    .WithReference(miccheckDb)
+    .WaitFor(miccheckDb)
+    .WithHttpEndpoint(port: 5000, name: "http");
 
 builder.AddViteApp("admin", "../admin", "serve")
     .WithReference(api)
     .WaitFor(api)
+    .WithHttpEndpoint(port: 5173, name: "http")
     .WithExternalHttpEndpoints();
 
 builder.Build().Run();