refactor!: reparent 87 sinks to HeraldSinkBase; reference Herald.OSS

Herald.OSS just unified its sink contract (every routed sink must
implement IKernelSink) and is the canonical upstream. Herald.Sinks
now references Herald.OSS directly — the former Modules/Core route
is retired — and every sink inherits from HeraldSinkBase to claim
IKernelSink automatically.

Step 2 — Directory.Build.props reference swap:
- Monorepo branch was: ProjectReference to ../Core/Herald.Core.csproj
  (sibling Modules/Core inside the umbrella).
- Monorepo branch is now: ProjectReference to
  ../../../Herald.OSS/Herald.OSS.csproj (sibling Herald.OSS clone at
  /e/dev/Herald.OSS/).
- Standalone branch unchanged: PackageReference to Herald.OSS NuGet
  pinned via $(HeraldCoreVersion).
- HeraldCoreVersion pin bumped from 1.0.0 to 0.1.0 to match the
  Herald.OSS upstream version.
- SinkAutoRegistrationGenerator ProjectReference moved from
  Modules/Generators/MMP.Herald.Generators.csproj to
  ../../../Herald.OSS/generators/MMP.Herald.OSS.Generators.csproj
  for the same reason — single upstream artifact.

Step 3 — sink reparent (mechanical sed pass across 87 sink class files):
- `: ILogger, IBatchedLogSink, IDisposable` → `: HeraldSinkBase, IBatchedLogSink, IDisposable`
- `: ILogger` → `: HeraldSinkBase`
- `public void Log(LogEvent` → `public override void Log(LogEvent`
- `using MMP.Herald.Sinks;` added after `using MMP.Herald;`

Each sink now gets:
- ILogger contract for free via HeraldSinkBase
- IKernelSink contract for free via HeraldSinkBase
- Default `Log(in LogEventBuffer)` that materialises through
  KernelBufferAdapter.MaterializeAndRender and forwards to the
  subclass's `Log(LogEvent)` override
- Subclasses keep their existing heap-event implementation unchanged

What this fixes:
- Before: a pipeline with any Herald.Sinks sink failed kernel
  eligibility because no sink implemented IKernelSink. Pipeline
  dropped to chain path: 812 ns / 1,160 B per emit, paid even by
  kernel-native sinks in the same fan-out (30× tax).
- After: every sink claims IKernelSink via the base; the kernel fast
  path activates regardless of sink mix. Sinks that need
  LogEvent.Message pay the per-sink boundary materialisation
  (~360 ns / ~760 B). Sinks that don't can override
  `Log(in LogEventBuffer)` to consume the buffer directly for true
  zero-allocation emit.

Contract tests updated to assert the new reference shape:
- DirectoryBuildProps_owns_the_Herald_OSS_reference and
  DirectoryBuildProps_has_both_monorepo_and_standalone_branches now
  check the sibling-clone Herald.OSS path instead of ../Core.
- HeraldCoreVersion_matches_Core_csproj_Version now cross-checks
  against Herald.OSS.csproj's Version (at ../../../Herald.OSS/).

Build: 0 warnings, 0 errors across net8/net9/net10.
Tests: 257/257 suites pass (1,800+ individual tests across the 98
sinks + Contract + helper suites).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: Steve Muchow

Directory.Build.props

@@ -22,14 +22,16 @@
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
 
     <!--
-      Version of Herald.OSS (the published NuGet package for Herald.Core)
-      that every sink in this repo depends on. Pinned here so a single
-      edit moves the whole sink ecosystem to a new Core release. Standalone
-      clones of Herald.Sinks (where Modules/Core/ isn't a sibling) restore
-      Herald.OSS from nuget.org at this version; the umbrella-monorepo
-      build uses the live ProjectReference instead and ignores the pin.
+      Version of Herald.OSS that every sink in this repo depends on.
+      Pinned here so a single edit moves the whole sink ecosystem to
+      a new Herald.OSS release. Standalone clones of Herald.Sinks
+      (where Herald.OSS isn't a sibling directory) restore Herald.OSS
+      from nuget.org at this version; the umbrella-monorepo build uses
+      a live ProjectReference to ../../../Herald.OSS/ instead and
+      ignores the pin. Herald.OSS is the canonical upstream — the
+      former Modules/Core route is retired.
     -->
-    <HeraldCoreVersion>1.0.0</HeraldCoreVersion>
+    <HeraldCoreVersion>0.1.0</HeraldCoreVersion>
   </PropertyGroup>
 
   <!--
@@ -134,74 +136,81 @@
        ctor into LogSinkProviderRegistry.Default at assembly load.
 
        Path is relative to this Directory.Build.props file:
-         MSBuildThisFileDirectory = Modules/Herald.Sinks/
-         + ..                     = Modules/
-         + Generators/MMP.Herald.Generators.csproj
+         MSBuildThisFileDirectory = /e/dev/Herald/Modules/Herald.Sinks/
+         + ..\..\..              = /e/dev/
+         + Herald.OSS/generators/MMP.Herald.OSS.Generators.csproj
        OutputItemType=Analyzer makes Roslyn load it as a generator;
        ReferenceOutputAssembly=false keeps the netstandard2.0
-       generator dll out of the sink's runtime closure. -->
-  <ItemGroup>
-    <ProjectReference Include="$(MSBuildThisFileDirectory)..\Generators\MMP.Herald.Generators.csproj">
+       generator dll out of the sink's runtime closure. The generator
+       lives in Herald.OSS so the entire sink ecosystem references a
+       single upstream artifact. -->
+  <ItemGroup Condition="Exists('$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\generators\MMP.Herald.OSS.Generators.csproj')">
+    <ProjectReference Include="$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\generators\MMP.Herald.OSS.Generators.csproj">
       <OutputItemType>Analyzer</OutputItemType>
       <ReferenceOutputAssembly>false</ReferenceOutputAssembly>
     </ProjectReference>
   </ItemGroup>
 
   <!--
-    Herald.OSS dependency — every sink references the Herald.Core
+    Herald.OSS dependency — every sink references the Herald.OSS
     library. Two resolution paths, picked automatically based on
-    whether this clone sits inside the umbrella monorepo:
-
-      * Monorepo  — Modules/Core/Herald.Core.csproj exists as a
-                    sibling. ProjectReference pulls the live source
-                    so a Core edit shows up immediately in every
-                    sink build. Private="false" + ExcludeAssets="runtime"
-                    keep Core out of the sink plugin's bin\, because
-                    Herald.Server / the host already loads Core and
-                    the plugin context resolves to that copy via
-                    AssemblyDependencyResolver.
-      * Standalone — Modules/Core/ does not exist (e.g. a fresh
-                    `git clone https://github.com/mmpworks/Herald.Sinks`
-                    outside the umbrella). PackageReference to
-                    Herald.OSS on nuget.org pinned at the
-                    HeraldCoreVersion declared above.
-
-    Per-sink csprojs do NOT declare a Herald.Core reference of their
+    whether the Herald.OSS repo is cloned as a sibling of the
+    Herald monorepo:
+
+      * Sibling clone — /e/dev/Herald.OSS/Herald.OSS.csproj exists
+                        relative to this monorepo at ../../../Herald.OSS/.
+                        ProjectReference pulls the live source so a
+                        Herald.OSS edit shows up immediately in every
+                        sink build. Private="false" + ExcludeAssets="runtime"
+                        keep Herald.OSS out of the sink plugin's bin\,
+                        because Herald.Server / the host already loads
+                        Herald.OSS and the plugin context resolves to
+                        that copy via AssemblyDependencyResolver.
+      * Standalone    — Herald.OSS is not present as a sibling (e.g. a
+                        fresh `git clone https://github.com/mmpworks/Herald.Sinks`
+                        outside the umbrella). PackageReference to
+                        Herald.OSS on nuget.org pinned at the
+                        HeraldCoreVersion declared above.
+
+    The former route through Modules/Core is retired — Herald.OSS is
+    the canonical upstream for the entire sink ecosystem.
+
+    Per-sink csprojs do NOT declare a Herald.OSS reference of their
     own — the right one comes from here. A sink that needs to override
-    (e.g. a private-fork experiment pinning a custom Core branch)
-    sets <HeraldSinkCustomCoreRef>true</HeraldSinkCustomCoreRef> in
-    its csproj and supplies its own reference; both ItemGroups below
+    (e.g. a private-fork experiment pinning a custom branch) sets
+    <HeraldSinkCustomCoreRef>true</HeraldSinkCustomCoreRef> in its
+    csproj and supplies its own reference; both ItemGroups below
     short-circuit on that flag.
   -->
   <!-- Sink-package branch: Private=false + ExcludeAssets=runtime is the
        plugin-packaging shape. The sink's .nupkg stays small, and at runtime
-       Herald.Server / the host has Core loaded — the plugin's
-       AssemblyLoadContext resolves Core to the host's copy. -->
-  <ItemGroup Condition="Exists('$(MSBuildThisFileDirectory)..\Core\Herald.Core.csproj') AND '$(HeraldSinkCustomCoreRef)' != 'true' AND '$(IsTestProject)' != 'true'">
-    <ProjectReference Include="$(MSBuildThisFileDirectory)..\Core\Herald.Core.csproj">
+       Herald.Server / the host has Herald.OSS loaded — the plugin's
+       AssemblyLoadContext resolves Herald.OSS to the host's copy. -->
+  <ItemGroup Condition="Exists('$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\Herald.OSS.csproj') AND '$(HeraldSinkCustomCoreRef)' != 'true' AND '$(IsTestProject)' != 'true'">
+    <ProjectReference Include="$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\Herald.OSS.csproj">
       <Private>false</Private>
       <ExcludeAssets>runtime</ExcludeAssets>
     </ProjectReference>
   </ItemGroup>
 
-  <!-- Test-project branch: standard reference. Core.dll flows into the
-       test bin\ so xunit can load the assembly and discover tests. There
-       is no plugin host loading Core for us in a test process. -->
-  <ItemGroup Condition="Exists('$(MSBuildThisFileDirectory)..\Core\Herald.Core.csproj') AND '$(HeraldSinkCustomCoreRef)' != 'true' AND '$(IsTestProject)' == 'true'">
-    <ProjectReference Include="$(MSBuildThisFileDirectory)..\Core\Herald.Core.csproj" />
+  <!-- Test-project branch: standard reference. Herald.OSS.dll flows into
+       the test bin\ so xunit can load the assembly and discover tests.
+       There is no plugin host loading Herald.OSS for us in a test process. -->
+  <ItemGroup Condition="Exists('$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\Herald.OSS.csproj') AND '$(HeraldSinkCustomCoreRef)' != 'true' AND '$(IsTestProject)' == 'true'">
+    <ProjectReference Include="$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\Herald.OSS.csproj" />
   </ItemGroup>
 
-  <ItemGroup Condition="!Exists('$(MSBuildThisFileDirectory)..\Core\Herald.Core.csproj') AND '$(HeraldSinkCustomCoreRef)' != 'true'">
+  <ItemGroup Condition="!Exists('$(MSBuildThisFileDirectory)..\..\..\Herald.OSS\Herald.OSS.csproj') AND '$(HeraldSinkCustomCoreRef)' != 'true'">
     <!--
       Standalone PackageReference: NO PrivateAssets / ExcludeAssets.
       A consumer doing `dotnet add package Herald.Sinks.Datadog` to a
       plain ASP.NET Core or worker app expects Herald.OSS.dll to flow
       into their bin\ alongside the sink — otherwise the first sink
       registration throws FileNotFoundException at runtime. The
-      monorepo branch above sets Private="false" + ExcludeAssets="runtime"
+      sibling-clone branch above sets Private="false" + ExcludeAssets="runtime"
       because plugins live inside an AssemblyLoadContext where the host
-      already loaded Core; that's a plugin-packaging optimisation, not
-      a NuGet-distribution policy.
+      already loaded Herald.OSS; that's a plugin-packaging optimisation,
+      not a NuGet-distribution policy.
     -->
     <PackageReference Include="Herald.OSS" />
   </ItemGroup>

src/Herald.Sinks.Aliyun/AliyunSlsLogSink.cs

@@ -12,6 +12,7 @@
 using System.Text.Json;
 using System.Threading;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
 using LogEvent = MMP.Herald.Events.LogEvent;
@@ -40,7 +41,7 @@ namespace Herald.Sinks.Aliyun;
 /// own auth handler on top.
 /// </para>
 /// </remarks>
-public sealed class AliyunSlsLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class AliyunSlsLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private readonly Uri _endpoint;
     private readonly string _accessKeyId;
@@ -77,7 +78,7 @@ public AliyunSlsLogSink(
         _httpClient = httpClient ?? new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch(new[] { logEvent });

src/Herald.Sinks.AmazonS3/AmazonS3LogSink.cs

@@ -12,6 +12,7 @@
 using Amazon.S3;
 using Amazon.S3.Model;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
 // AWS SDK doesn't shadow Herald's LogEvent, but we alias for consistency.
@@ -37,7 +38,7 @@ namespace Herald.Sinks.AmazonS3;
 /// rely on an IAM role attached to the compute platform.
 /// </para>
 /// </remarks>
-public sealed class AmazonS3LogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class AmazonS3LogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private readonly IAmazonS3 _client;
     private readonly bool _ownsClient;
@@ -80,7 +81,7 @@ public AmazonS3LogSink(
         _keyPrefix = keyPrefix.TrimEnd('/');
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch(new[] { logEvent });

src/Herald.Sinks.ApplicationInsightsHttp/ApplicationInsightsLogSink.cs

@@ -10,6 +10,7 @@
 using System.Text.Json;
 using System.Threading;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Events;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
@@ -43,7 +44,7 @@ namespace Herald.Sinks.ApplicationInsightsHttp;
 /// end-to-end batching; the sink itself does not buffer.
 /// </para>
 /// </remarks>
-public sealed class ApplicationInsightsLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class ApplicationInsightsLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private readonly ApplicationInsightsConnectionString _connection;
     private readonly string? _roleName;
@@ -61,7 +62,7 @@ public ApplicationInsightsLogSink(
         _httpClient = httpClient ?? new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch([logEvent]);

src/Herald.Sinks.ApplicationInsightsSdk/ApplicationInsightsLogSink.cs

@@ -8,6 +8,7 @@
 using Microsoft.ApplicationInsights.DataContracts;
 using Microsoft.ApplicationInsights.Extensibility;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using LogEvent = MMP.Herald.Events.LogEvent;
 
@@ -33,7 +34,7 @@ namespace Herald.Sinks.ApplicationInsightsSdk;
 /// pass <c>InstrumentationKey={key}</c>.
 /// </para>
 /// </remarks>
-public sealed class ApplicationInsightsLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class ApplicationInsightsLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private readonly TelemetryClient _client;
     private readonly TelemetryConfiguration? _ownedConfig;
@@ -58,7 +59,7 @@ public ApplicationInsightsLogSink(TelemetryClient client)
         _ownedConfig = null;
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
 

src/Herald.Sinks.AwsCloudWatch/AwsCloudWatchLogSink.cs

@@ -13,6 +13,7 @@
 using Amazon.CloudWatchLogs;
 using Amazon.CloudWatchLogs.Model;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
 // AWS SDK ships its own LogEvent type in Amazon.CloudWatchLogs.Model.
@@ -51,7 +52,7 @@ namespace Herald.Sinks.AwsCloudWatch;
 /// failing the batch.
 /// </para>
 /// </remarks>
-public sealed class AwsCloudWatchLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class AwsCloudWatchLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private const int MaxBatchEvents = 10_000;
     private const int MaxEventBytes = 262_144;  // 256 KB single-event ceiling
@@ -109,7 +110,7 @@ public AwsCloudWatchLogSink(
         _autoCreateLogStream = autoCreateLogStream;
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch(new[] { logEvent });

src/Herald.Sinks.Axiom/AxiomLogSink.cs

@@ -10,6 +10,7 @@
 using System.Text;
 using System.Text.Json;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using LogEvent = MMP.Herald.Events.LogEvent;
 
@@ -20,7 +21,7 @@ namespace Herald.Sinks.Axiom;
 /// (api.axiom.co/v1/datasets/{dataset}/ingest). Bearer-token auth, JSON
 /// array body. HTTP-only.
 /// </summary>
-public sealed class AxiomLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class AxiomLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private const string DefaultBase = "https://api.axiom.co/v1/datasets/";
 
@@ -39,7 +40,7 @@ public AxiomLogSink(string apiToken, string dataset, string? baseUrl = null, Htt
         _http = httpClient ?? new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
     }
 
-    public void Log(LogEvent logEvent) => LogBatch(new[] { logEvent });
+    public override void Log(LogEvent logEvent) => LogBatch(new[] { logEvent });
 
     public void LogBatch(IReadOnlyList<LogEvent> events)
     {

src/Herald.Sinks.AzureAnalytics/AzureAnalyticsLogSink.cs

@@ -12,6 +12,7 @@
 using System.Text.Json;
 using System.Threading;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Events;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
@@ -47,7 +48,7 @@ namespace Herald.Sinks.AzureAnalytics;
 /// to ~30,000 events per batch, far above typical pipeline sizing.
 /// </para>
 /// </remarks>
-public sealed class AzureAnalyticsLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class AzureAnalyticsLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private const string ApiVersion = "2016-04-01";
     private const string ResourcePath = "/api/logs";
@@ -86,7 +87,7 @@ public AzureAnalyticsLogSink(
         _httpClient = httpClient ?? new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch(new[] { logEvent });

src/Herald.Sinks.AzureBlobStorage/AzureBlobStorageLogSink.cs

@@ -12,6 +12,7 @@
 using Azure.Storage.Blobs;
 using Azure.Storage.Blobs.Models;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
 using LogEvent = MMP.Herald.Events.LogEvent;
@@ -37,7 +38,7 @@ namespace Herald.Sinks.AzureBlobStorage;
 /// tail prevents collisions under concurrent flushes.
 /// </para>
 /// </remarks>
-public sealed class AzureBlobStorageLogSink : ILogger, IBatchedLogSink
+public sealed class AzureBlobStorageLogSink : HeraldSinkBase, IBatchedLogSink
 {
     private readonly BlobContainerClient _container;
     private readonly string _keyPrefix;
@@ -74,7 +75,7 @@ public AzureBlobStorageLogSink(
         _keyPrefix = keyPrefix.TrimEnd('/');
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch(new[] { logEvent });

src/Herald.Sinks.AzureCosmosDB/AzureCosmosDbLogSink.cs

@@ -10,6 +10,7 @@
 using System.Text.Json;
 using Microsoft.Azure.Cosmos;
 using MMP.Herald;
+using MMP.Herald.Sinks;
 using MMP.Herald.Pipeline;
 using MMP.Herald.Services;
 using LogEvent = MMP.Herald.Events.LogEvent;
@@ -37,7 +38,7 @@ namespace Herald.Sinks.AzureCosmosDB;
 /// 1.0 — follow-up feature.
 /// </para>
 /// </remarks>
-public sealed class AzureCosmosDbLogSink : ILogger, IBatchedLogSink, IDisposable
+public sealed class AzureCosmosDbLogSink : HeraldSinkBase, IBatchedLogSink, IDisposable
 {
     private readonly CosmosClient _client;
     private readonly bool _ownsClient;
@@ -83,7 +84,7 @@ public AzureCosmosDbLogSink(
         _partitionKeyProperty = partitionKeyProperty;
     }
 
-    public void Log(LogEvent logEvent)
+    public override void Log(LogEvent logEvent)
     {
         ArgumentNullException.ThrowIfNull(logEvent);
         LogBatch(new[] { logEvent });