rewrite comments in neutral, terse style

Doc comments, inline comments, and README no longer editorialize about
the code (ActiveRecord, leak, fake, Yak before/after). They now describe
behavior only. Test A_client_can_reach_its_DbContext__the_leak renamed
to A_client_can_reach_its_DbContext. No behavior changes; all 27 tests
pass.

src/Before/WebApp.cs

@@ -1,19 +1,13 @@
 namespace Before;
 
 /// <summary>
-/// The consuming application. In the "before" situation it talks to the
-/// DB-backed domain model directly: its methods take <see cref="Client"/> and
-/// <see cref="Order"/> (which inherit <see cref="DbBase"/>) as parameters.
-///
-/// One of its methods reaches the <see cref="DbContext"/> *through* a domain
-/// object — the leak. In the "after" situation (Yak 02) the WebApp consumes
-/// DTOs instead, and the domain objects no longer expose a DbContext.
+/// Consumes <see cref="Client"/> and <see cref="Order"/> domain objects
+/// directly.
 /// </summary>
 public class WebApp
 {
     /// <summary>
-    /// Render a client together with all of its orders, consuming the
-    /// <see cref="Client"/>/ <see cref="Order"/> domain objects directly.
+    /// Returns the client's name, id, and orders formatted as text.
     /// </summary>
     public string ShowClient(Client client)
     {
@@ -25,13 +19,7 @@ public class WebApp
         return string.Join(Environment.NewLine, lines);
     }
 
-    /// <summary>
-    /// The leak, made concrete: from a plain domain object the WebApp can reach
-    /// the <see cref="DbContext"/> (<see cref="DbBase.DbContext"/>) and thus
-    /// touch the persistence layer — here just to ask whether the client has
-    /// been saved. The "after" situation removes <c>client.DbContext</c>
-    /// entirely, so no DTO-consumer can do this.
-    /// </summary>
+    /// <summary>Returns true when the client is attached to a context.</summary>
     public bool IsPersisted(Client client)
     {
         ArgumentNullException.ThrowIfNull(client);