docs: update CLAUDE.md with verified build and test commands

Remove template UnitTest1.cs placeholder. Add actual project structure,
run commands for the NATS server host, and update test command examples
to reference the real project paths.

CLAUDE.md

@@ -10,6 +10,8 @@ NATS is a high-performance publish-subscribe messaging system. It supports wildc
 
 ## Build & Test Commands
 
+The solution file is `NatsDotNet.slnx`.
+
 ```bash
 # Build the solution
 dotnet build
@@ -17,19 +19,54 @@ dotnet build
 # Run all tests
 dotnet test
 
-# Run a single test project
-dotnet test <path/to/TestProject.csproj>
-
-# Run a specific test by name
-dotnet test --filter "FullyQualifiedName~TestClassName.TestMethodName"
-
 # Run tests with verbose output
 dotnet test -v normal
 
+# Run a single test project
+dotnet test tests/NATS.Server.Tests
+
+# Run a specific test by name
+dotnet test tests/NATS.Server.Tests --filter "FullyQualifiedName~TestName"
+
+# Run the NATS server (default port 4222)
+dotnet run --project src/NATS.Server.Host
+
+# Run the NATS server on a custom port
+dotnet run --project src/NATS.Server.Host -- -p 14222
+
 # Clean and rebuild
 dotnet clean && dotnet build
 ```
 
+## .NET Project Structure
+
+```
+NatsDotNet.slnx                           # Solution file
+src/
+  NATS.Server/                            # Core server library
+    NatsServer.cs                         # Server: listener, accept loop, shutdown
+    NatsClient.cs                         # Per-connection client: read/write loops, sub tracking
+    NatsOptions.cs                        # Server configuration (port, host, etc.)
+    Protocol/
+      NatsParser.cs                       # Protocol state machine (PUB, SUB, UNSUB, etc.)
+      NatsProtocol.cs                     # Wire-level protocol writing (INFO, MSG, PING/PONG)
+    Subscriptions/
+      SubjectMatch.cs                     # Subject validation and wildcard matching
+      SubList.cs                          # Trie-based subscription list with caching
+      SubListResult.cs                    # Match result container (plain subs + queue groups)
+      Subscription.cs                     # Subscription model (subject, sid, queue, client)
+  NATS.Server.Host/                       # Executable host app
+    Program.cs                            # Entry point, CLI arg parsing (-p port)
+tests/
+  NATS.Server.Tests/                      # xUnit test project
+    ParserTests.cs                        # Protocol parser tests
+    SubjectMatchTests.cs                  # Subject validation & matching tests
+    SubListTests.cs                       # Subscription list trie tests
+    ClientTests.cs                        # Client-level protocol tests
+    ServerTests.cs                        # Server pubsub/wildcard tests
+    IntegrationTests.cs                   # End-to-end tests using NATS.Client.Core NuGet
+```
+
 ## Go Reference Commands
 
 ```bash

tests/NATS.Server.Tests/UnitTest1.cs

@@ -1,10 +0,0 @@
-namespace NATS.Server.Tests;
-
-public class UnitTest1
-{
-    [Fact]
-    public void Test1()
-    {
-
-    }
-}