[cross-repo from server#350] Conformance blocker: complete child-workflows parity coverage (#137)

Author: durable-workflow-ops

CONFORMANCE.md

@@ -19,12 +19,13 @@ The Python SDK claims two targets from the suite's matrix:
 - `worker_protocol_implementation` — worker plane and frozen history
   event replay.
 
-## Fixture sources served by this repo
+## Fixture and runtime scenario sources
 
 | Category | Source path | Status |
 | --- | --- | --- |
 | `control_plane_request_response` | `tests/fixtures/control-plane/` | stable, parity-shared with `cli` |
 | `signal_query_runtime_contract` | `tests/test_signals.py`, `tests/test_queries.py`, `tests/test_worker.py` | stable, parity-shared with PHP worker, CLI, and server routes |
+| `namespace_runtime_contract` | public scenario manifest at <https://durable-workflow.github.io/platform-conformance/namespace-runtime-scenarios.json> | stable, suite v6 runtime coverage for namespace isolation and SDK namespace selection |
 | `worker_task_lifecycle` | `tests/fixtures/external-task-input/`, `tests/fixtures/external-task-result/` | stable |
 | `history_replay_bundles` | `tests/fixtures/golden_history/` and the public replay scenario manifest at <https://durable-workflow.github.io/platform-conformance/replay-runtime-scenarios.json> | stable, parity-shared with `workflow` golden bundles and the full runtime replay scenario matrix |
 
@@ -35,6 +36,8 @@ The fixtures in this repo are exercised today by:
 - `tests/test_signals.py`
 - `tests/test_queries.py`
 - `tests/test_worker.py`
+- `tests/test_replay.py`
+- `tests/test_golden_history_replay.py`
 - `scripts/check-cli-parity.py`
 - the `cli-parity` job in `.github/workflows/ci.yml`
 
@@ -51,7 +54,7 @@ result document before tag, with the conformance level at `full` or
 | Field | Value |
 | --- | --- |
 | Required claimed targets | `official_sdk`, `worker_protocol_implementation` |
-| Required suite version | `PlatformConformanceSuite::VERSION` (currently `5`, mirrored at `/platform-conformance-contract.json`) |
+| Required suite version | `PlatformConformanceSuite::VERSION` (currently `6`, mirrored at `/platform-conformance-contract.json`) |
 | CI job | `platform-conformance` (lands when the harness reference implementation publishes; until then `cli-parity` and `test_history_event_contract.py` cover the same ground) |
 | Block on `nonconforming` | yes |
 | Artifact attached to release | harness result document, schema `durable-workflow.v2.platform-conformance.result` |
@@ -95,6 +98,8 @@ no test in this repo notices.
   <https://durable-workflow.github.io/docs/2.0/platform-conformance>
 - Public static suite manifest:
   <https://durable-workflow.github.io/platform-conformance-contract.json>
+- Namespace runtime scenarios:
+  <https://durable-workflow.github.io/platform-conformance/namespace-runtime-scenarios.json>
 - Compatibility authority:
   <https://durable-workflow.github.io/docs/2.0/compatibility>
 - Polyglot parity doc: