Add durable execution conformance test harness (.NET, step suite)

[GarrettBeatty]

Summary

Wires the .NET Durable Execution SDK into the language-neutral aws-durable-execution-conformance-tests runner. The runner deploys a SAM template, invokes each mapped Lambda, and validates the durable execution result and event history against language-agnostic requirement specs.

All nine conformance suites are implemented and passing. Handlers are ported from the prior internal .NET implementation in DurableExecutionsSDKTestingFramework/examples/dotnet, adapted so each handler project references the in-repo SDK directly (no SDK copy/pack step).

Verified end-to-end against real AWS (us-east-1)

Every suite deployed, invoked, and validated — 122 passed, 0 failed:

Suite	Passed	NotImplemented	Total
step	20	0	20
wait	5	0	5
child	17	1	18
callback	19	0	19
invoke	15	1	16
wait_for_condition	13	0	13
wait_for_callback	15	0	15
parallel	21	1	22
map	17	3	20

The 6 NotImplemented requirements (3-14, 5-16, 8-15, 9-14, 9-19, 9-20) are all custom-serdes cases: the .NET SDK has no per-operation serializer slot — all payloads flow through the one registered ILambdaSerializer (matching the Java approach). They're declared under TestingMetadata.NotImplemented so the runner reports them as non-blocking gaps rather than silent omissions.

What's included

• Conformance/ under Amazon.Lambda.DurableExecution.IntegrationTests:
  • template_<suite>.yaml per suite — maps each function to its requirement id(s) via TestingMetadata.TestDescription; deploys on the dotnet8 managed runtime with the makefile build method.
  • <suite>/<Handler>/ — one executable handler project per requirement (144 handlers total).
  • scripts/build_examples.sh (publish handlers → publish/<Fn>/, incl. the InvokeEchoTarget→InvokeEchoTargetTenant tenancy alias), discover_suites.py (CI matrix), inject_execution_role.py (CI role injection).
  • README.md, .gitignore.
• .github/workflows/conformance-tests.yml — per-suite matrix job: publish handlers → pip-install runner → OIDC creds → inject execution role → run suite → upload JUnit report.
• Excludes Conformance/** from the parent test project's compile glob so the standalone handler types don't collide.

Notable handler details

• Retry-across-invocation tests (step 1-11/1-13/1-14/1-15/1-18, child 3-7/3-12) count attempts across invocations, which the replay model can't hold in memory, so they use the AttemptsTable DynamoDB table.
• invoke deploys two callee target functions (InvokeEchoTarget, InvokeFailTarget) invoked via AWSSDK.Lambda; ARNs wired via env vars + Fn::GetAtt. The tenancy test (5-8) reuses the echo binary under a second logical id (InvokeEchoTargetTenant, PER_TENANT isolation) produced by build-time aliasing.
• child 3-11/3-17 and step 1-17/1-18 log via the durable context logger (records carry durableExecutionArn, which the runner's CloudWatch filter keys on — plain Console.WriteLine is dropped). 3-11 disables replay-aware filtering so the ReplayChildren re-execution is also observed (expects the line logged twice).

Before CI can run

Set the repo secrets CONFORMANCE_DEPLOY_ROLE_ARN (SAM-capable deploy role) and CONFORMANCE_LAMBDA_EXECUTION_ROLE_ARN, plus (optionally) the CONFORMANCE_AWS_REGION variable (defaults to us-east-1).

Notes

• Test-only infrastructure — no shipping library change, so this carries the Release Not Needed label.
• Upstream nit: on Windows the runner crashes printing ✅ under cp1252; PYTHONUTF8=1 works around it (does not affect the Linux CI runner).

[GarrettBeatty]

will configure all of this after this pr is merged. i ran the conformance test locally and it passes

[GarrettBeatty]

i think i may need to modify this slightly to work with the existing buildspec etc but ill do that in a follow up pr

[GarrettBeatty]

this code was all approved already in the internal git farm repo by alex