Optimize event and stack paging totals

[ejsmith]

Summary

• Adds an include=total query option to event list endpoints so cursor paging can opt into total metadata only when needed.
• Updates event and stack pages to request totals only when they are useful for stable initial pagination metadata.
• Replaces stack total calculation based on sum_other_doc_count with an optional stack_id cardinality aggregation, and preserves known table page counts when later offset responses omit totals.
• Updates the Foundatio.Repositories.Elasticsearch package to 8.0.0-beta2 without using PIT.

Root Cause

Event paging was asking Elasticsearch for exact totals on every before/after request and still returning X-Result-Count on cursor hops. Stack paging was also deriving a stack total from terms aggregation spillover document counts, which is not a stable distinct stack count.

Validation

• dotnet restore src/Exceptionless.Web/Exceptionless.Web.csproj
• dotnet build src/Exceptionless.Web/Exceptionless.Web.csproj -p:UseSharedCompilation=false -p:BuildInParallel=false --no-restore
• dotnet build tests/Exceptionless.Tests/Exceptionless.Tests.csproj -p:UseSharedCompilation=false -p:BuildInParallel=false --no-restore
• UPDATE_SNAPSHOTS=true dotnet test tests/Exceptionless.Tests/Exceptionless.Tests.csproj -- --filter-class Exceptionless.Tests.Controllers.OpenApiControllerTests
• dotnet test tests/Exceptionless.Tests/Exceptionless.Tests.csproj -- --filter-class Exceptionless.Tests.Controllers.OpenApiControllerTests
• npm run check
• npm run test:unit -- src/lib/features/shared/table.test.ts
• git diff --check
• UPDATE_SNAPSHOTS=true dotnet test tests/Exceptionless.Tests/Exceptionless.Tests.csproj -- --filter-class Exceptionless.Tests.Controllers.OpenApiControllerTests
• dotnet test tests/Exceptionless.Tests/Exceptionless.Tests.csproj -- --filter-class Exceptionless.Tests.Controllers.OpenApiControllerTests
• dotnet build src/Exceptionless.Web/Exceptionless.Web.csproj -p:UseSharedCompilation=false -p:BuildInParallel=false --no-restore
• npm run check

Notes

• PIT is intentionally not used because there is not a reliable cleanup path and it is not required for this change.
• Missing include does not include total metadata; clients must pass include=total when they need X-Result-Count.
• Aspire was started locally and reported the API and Svelte app healthy on dynamic ports.

[ejsmith]

/preview

[github-actions]

Preview deployed

• App: https://dev-app.exceptionless.io
• Collector: https://dev-collector.exceptionless.io
• Commit: 9c885b3506aa
• Version: 8.5.3-preview.paging-include-total.0.18
• Workflow run: view logs

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
Exceptionless.AppHost	39%	40%	134	❌
Exceptionless.Core	70%	63%	7967	➖
Exceptionless.Insulation	24%	23%	203	❌
Exceptionless.Web	72%	61%	4147	➖
Summary	69% (14207 / 20566)	61% (7370 / 11994)	12451	➖