feat(di): support atomic config reload

[thomhurst]

Summary

• add opt-in AddReloadingShield registration with atomic IShieldProvider snapshots
• retain the last known-good snapshot on invalid configuration and contain failure-callback exceptions
• keep in-flight executions on their original immutable pipeline and reset strategy state after valid replacement
• expose fixed providers for ordinary named shields so mixed registrations preserve last-registration-wins semantics
• document registry/keyed snapshot behavior, disposal, state reset, and the zero-allocation current-snapshot fast path

Validation

• dotnet build Kevlar.slnx -c Release
• unit tests: 542 passed
• integration tests: 16 passed
• analyzer tests: 19 passed
• allocation tests: 2 passed
• netstandard tests: 1 passed
• Docusaurus production build
• documentation snippets: 81 compiled; runtime examples passed
• package layout, metadata, consumer, analyzer, trimmed and single-file checks passed (NativeAOT remains Linux CI-only)
• BenchmarkDotNet: direct snapshot 0.604 ns / 0 B; reload-aware Current 0.592 ns / 0 B

Closes #73

[coderabbitai]

Warning

Review limit reached

@thomhurst, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 8 minutes

Limit details: You’ve used all 10 included reviews currently available.

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

How can I continue?

Wait for the limit to reset, then comment @coderabbitai review or push new commits to the PR.

An organization admin can change what happens after included review limits in Billing.

How do review limits work?

CodeRabbit enforces per-developer PR review limits within each organization.

For paid Pro and Pro+ reviews, CodeRabbit uses a developer's included PR review attempts over the past 7 days to set the current hourly allowance. At typical activity levels, the full plan allowance applies. Higher sustained activity can lower the allowance until earlier attempts leave the 7-day window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 04db8ae7-ca4f-46ee-a6b2-fa7fe6fc22b6

📥 Commits

Reviewing files that changed from the base of the PR and between 4f43251 and 7725843.

📒 Files selected for processing (15)

• Directory.Packages.props
• benchmarks/Kevlar.Benchmarks/Kevlar.Benchmarks.csproj
• benchmarks/Kevlar.Benchmarks/ReloadingShieldProviderBenchmarks.cs
• docs/docs/dependency-injection.md
• scripts/Verify-Packages.ps1
• src/Kevlar.Extensions.DependencyInjection/FixedShieldProvider.cs
• src/Kevlar.Extensions.DependencyInjection/IKevlarRegistry.cs
• src/Kevlar.Extensions.DependencyInjection/IShieldProvider.cs
• src/Kevlar.Extensions.DependencyInjection/Kevlar.Extensions.DependencyInjection.csproj
• src/Kevlar.Extensions.DependencyInjection/KevlarRegistry.cs
• src/Kevlar.Extensions.DependencyInjection/KevlarServiceCollectionExtensions.cs
• src/Kevlar.Extensions.DependencyInjection/PublicAPI.Unshipped.txt
• src/Kevlar.Extensions.DependencyInjection/ReloadingShieldProvider.cs
• tests/Kevlar.Tests/DependencyInjectionContractTests.cs
• tests/Kevlar.Tests/ReloadingShieldTests.cs

---

_{Comment @coderabbitai help to get the list of available commands.}