Fix 6 tutorials with code snippets mismatched against actual source code

[Copilot]

Fresh new-developer audit of all 50 tutorials, cross-referencing every code snippet against the actual source. 44 passed; 6 had stale or incorrect API references that would confuse a mid-level dev following along.

Fixes

• Tutorial 08 (Activities Pipeline) — PipelineOptions showed non-existent properties (InputTopic, WorkerConcurrency, ProcessingTimeout); updated to actual (InboundSubject, NatsUrl, WorkflowTimeout, etc.). Changed SubscribeAsync<object> → SubscribeAsync<JsonElement>.

• Tutorial 26 (Message Replay) — IMessageReplayStore methods showed CancellationToken ct = default but actual interface requires the parameter (no default).

• Tutorial 29 (Throttle) — "What You'll Learn" listed wrong partition strategies (Source, Recipient, CorrelationId) → actual API: TenantId, Queue, Endpoint.

• Tutorial 31 (Event Sourcing) — CancellationToken param named ct in 5 snippets but source uses cancellationToken throughout IEventStore, TemporalQuery, ISnapshotStore.

• Tutorial 43 (Kubernetes) — Helm template listing showed deployment.yaml, service.yaml, ingress.yaml which don't exist. Updated to actual service-specific manifests (admin-api.yaml, openclaw-web.yaml, workflow-temporal.yaml, etc.).

• Tutorial 49 (Testing) — Referenced non-existent ITestWorkflowEnvironment / TestWorkflowEnvironment. Fixed to WorkflowEnvironment? / WorkflowEnvironment with the try-catch pattern used in the actual test suite.

Example (Tutorial 08 before/after)

// Before — properties don't exist on PipelineOptions
await _consumer.SubscribeAsync<object>(
    topic: _options.InputTopic, ...);

// After — matches src/Demo.Pipeline/IntegrationPipelineWorker.cs
await _consumer.SubscribeAsync<JsonElement>(
    topic: _options.InboundSubject, ...);