Server: start a retried write transaction from the database, not from the attempt that failed

src/DodoSSH.Api/Setup/Persistence.cs

@@ -1,5 +1,6 @@
 using DodoSSH.Infrastructure;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Diagnostics;
 using Microsoft.Extensions.Diagnostics.HealthChecks;
 using Microsoft.Extensions.Options;
 using Npgsql;
@@ -29,14 +30,18 @@ internal static class Persistence
             ?? throw new InvalidOperationException(
                 $"ConnectionStrings:{ConnectionStringName} is not configured.");
 
-        services.AddDbContext<DodoDbContext>(options => options
+        services.AddDbContext<DodoDbContext>((provider, options) => options
             .UseNpgsql(connectionString, npgsql => npgsql
                 .MigrationsHistoryTable("__EFMigrationsHistory", DodoDbContext.SchemaName)
-                // Retry on transient faults only. Note this is safe here because writes go
-                // through explicitly-managed transactions rather than relying on the execution
-                // strategy to replay ambient ones.
+                // Retry on transient faults only. A write transaction replayed by the strategy runs on
+                // the same context, which still holds what the failed attempt tracked — every such
+                // transaction goes through FreshAttempts.ExecuteFreshAsync, which starts a retry from
+                // the database instead.
                 .EnableRetryOnFailure(3))
-            .UseSnakeCaseNamingConvention());
+            .UseSnakeCaseNamingConvention()
+            // None in production. The seam a test uses to make a commit fail the way a dropped
+            // connection would, which is the only way to watch a retry happen.
+            .AddInterceptors(provider.GetServices<IInterceptor>()));
 
         services.AddHealthChecks()
             .AddCheck<DatabaseHealthCheck>(