feat(http): configure standard shield

[thomhurst]

Summary

• expose StandardHttpShieldOptions for every standard pipeline stage
• add registration-time and service-provider-aware AddStandardShield callbacks
• snapshot handler configuration while preserving documented shield state lifetimes
• document configuration and add an HTTP baseline benchmark

Benchmark

Case	Mean	Allocated
Before	500.674 ns	600 B
After	508.168 ns	600 B

The 1.5% mean difference is within overlapping confidence intervals; allocation is unchanged.

Test plan

• dotnet build Kevlar.slnx -c Release
• dotnet run --project tests/Kevlar.Tests -c Release --no-build -- --timeout 5m (678 passed)
• dotnet run --project tests/Kevlar.IntegrationTests -c Release --no-build -- --timeout 5m (108 passed)
• dotnet run --project tests/Kevlar.NetStandard.Tests -c Release --no-build -- --timeout 5m (5 passed)
• npm run build --prefix docs
• pwsh scripts/Verify-DocSnippets.ps1 -PackagesPath artifacts/package/release -Version 0.0.0-issue126
• pwsh scripts/Verify-Packages.ps1 -PackagesPath artifacts/package/release -Version 0.0.0-local

Closes #126

[coderabbitai]

Warning

Review limit reached

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

Next review available in: 18 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: 788bb36a-5407-4441-a814-f42912363038

📥 Commits

Reviewing files that changed from the base of the PR and between d44e515 and ca00093.

📒 Files selected for processing (7)

• benchmarks/Kevlar.Benchmarks/HttpReplayBenchmarks.cs
• docs/docs/http.md
• src/Kevlar.Extensions.Http/HttpShield.cs
• src/Kevlar.Extensions.Http/PublicAPI.Unshipped.txt
• src/Kevlar.Extensions.Http/ShieldHttpClientBuilderExtensions.cs
• src/Kevlar.Extensions.Http/StandardHttpShieldOptions.cs
• tests/Kevlar.Tests/HttpContractTests.cs

---

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