Propagate event-store OCC so projection scope can retry

[eanzhao]

Problem

ProjectionScopeGAgentBase.DispatchObservationAsync catches every dispatch failure and downgrades it to a warning. That means transient optimistic-concurrency conflicts on the scope's own event stream — exactly what actor-based event sourcing is designed to retry — get silently swallowed. The watermark-advanced event never lands, the scope sits on a stale version, and downstream consumers observe gaps with no follow-up retry.

Production log shows the symptom:

```
fail: Aevatar.Foundation.Core.EventSourcing.EventSourcingBehavior[0]
Event sourcing commit failed. agentId=projection.durable.scope:channel-bot-registration:channel-bot-registration-store eventType=ProjectionScopeWatermarkAdvancedEvent version=4 elapsedMs=3.6452 result=failed
System.InvalidOperationException: Optimistic concurrency conflict: expected 4, actual 5
warn: Aevatar.CQRS.Projection.Core.Orchestration.ProjectionMaterializationScopeGAgent[0]
Projection scope observation handling failed.
System.InvalidOperationException: Optimistic concurrency conflict: expected 4, actual 5
```

The warning swallowed a retryable conflict that should have driven the actor runtime to reload state and retry with the correct version.

Solution

• Introduce typed EventStoreOptimisticConcurrencyException (subclasses InvalidOperationException, keeps the original message format for backward compatibility) exposing agentId / expectedVersion / actualVersion as typed properties.
• Replace the generic InvalidOperationException raised by the three event-store implementations (GarnetEventStore, FileEventStore, InMemoryEventStore) with the typed exception.
• Add internal ProjectionObservationFailurePolicy.ShouldPropagate(...) that recognizes the OCC exception directly, through ProjectionDispatchAggregateException, through AggregateException, and through inner-exception chains.
• Let ProjectionScopeGAgentBase rethrow when the policy says "propagate" and keep swallowing deterministic failures (projector bugs) to avoid retry loops.
• Add regression tests covering direct, aggregate-wrapped, and non-OCC failure cases.

Impact

• src/Aevatar.Foundation.Abstractions/Persistence/EventStoreOptimisticConcurrencyException.cs (new)
• src/Aevatar.CQRS.Projection.Core/AssemblyInfo.cs (new, exposes internals to tests)
• src/Aevatar.CQRS.Projection.Core/Orchestration/ProjectionObservationFailurePolicy.cs (new)
• src/Aevatar.CQRS.Projection.Core/Orchestration/ProjectionScopeGAgentBase.cs
• src/Aevatar.Foundation.Runtime.Persistence.Implementations.Garnet/GarnetEventStore.cs
• src/Aevatar.Foundation.Runtime/Persistence/FileEventStore.cs
• src/Aevatar.Foundation.Runtime/Persistence/InMemoryEventStore.cs
• test/Aevatar.CQRS.Projection.Core.Tests/ProjectionObservationFailurePolicyTests.cs (new)

Existing consumers remain compatible:

• EventSourcingBehavior.ConfirmEventsAsync uses catch(Exception) — unaffected.
• GarnetEventStoreIntegrationTests asserts InvalidOperationException + message pattern — still passes because the new type subclasses InvalidOperationException and preserves the message format.
• Test doubles in other projects (HouseholdEntityDeviceInboundTests, ChannelBotRegistrationStoreTests, etc.) keep their own in-process InvalidOperationException; they exercise caller behavior, not the projection-scope retry path, so the asymmetry is acceptable.

Test plan

• dotnet test test/Aevatar.CQRS.Projection.Core.Tests/Aevatar.CQRS.Projection.Core.Tests.csproj --nologo — 99 pass, 1 skip (ES integration)
• dotnet test test/Aevatar.Foundation.Core.Tests/Aevatar.Foundation.Core.Tests.csproj --nologo — 159 pass
• dotnet test test/Aevatar.Foundation.Runtime.Hosting.Tests/Aevatar.Foundation.Runtime.Hosting.Tests.csproj --nologo --filter "FullyQualifiedName~GarnetEventStore" — 1 pass, 2 skip (require live Garnet)
• CI: architecture + solution-split guards

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 90.90909% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.07%. Comparing base (0a15750) to head (c7c4c5b).
⚠️ Report is 5 commits behind head on dev.

Files with missing lines	Patch %	Lines
...istence.Implementations.Garnet/GarnetEventStore.cs	0.00%	4 Missing ⚠️

@@            Coverage Diff             @@
##              dev     #365      +/-   ##
==========================================
+ Coverage   70.04%   70.07%   +0.03%     
==========================================
  Files        1155     1157       +2     
  Lines       82584    82623      +39     
  Branches    10868    10872       +4     
==========================================
+ Hits        57842    57895      +53     
+ Misses      20563    20551      -12     
+ Partials     4179     4177       -2     

Flag	Coverage Δ
ci	70.07% <90.90%> (+0.03%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...rchestration/ProjectionObservationFailurePolicy.cs	100.00% <100.00%> (ø)
...on.Core/Orchestration/ProjectionScopeGAgentBase.cs	75.46% <100.00%> (+7.27%)	⬆️
...stence/EventStoreOptimisticConcurrencyException.cs	100.00% <100.00%> (ø)
...r.Foundation.Runtime/Persistence/FileEventStore.cs	71.28% <100.00%> (+0.29%)	⬆️
...undation.Runtime/Persistence/InMemoryEventStore.cs	92.98% <100.00%> (+0.52%)	⬆️
...istence.Implementations.Garnet/GarnetEventStore.cs	0.00% <0.00%> (ø)

... and 2 files with indirect coverage changes

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