Fix PowerShell HelloCities: wire $starter binding, add local.settings.json

[Copilot]

The PowerShell HTTP starter functions declared a durableClient binding named starter in function.json but never surfaced or used it, causing the durable client to be unbound at runtime. The Quick Run instructions also lacked any setup for DURABLE_TASK_SCHEDULER_CONNECTION_STRING, making func start fail to connect.

Changes

• StartChaining/run.ps1, StartFanOutFanIn/run.ps1 — Added $starter to param(...) and passed -DurableClient $starter to Start-DurableOrchestration and New-DurableOrchestrationCheckStatusResponse:

  param($Request, $starter, $TriggerMetadata)
  
  $instanceId = Start-DurableOrchestration -FunctionName 'ChainingOrchestration' -DurableClient $starter
  $response = New-DurableOrchestrationCheckStatusResponse -Request $Request -InstanceId $instanceId -DurableClient $starter
  Push-OutputBinding -Name Response -Value $response

• local.settings.json — Added pre-configured settings for the emulator (mirrors the pattern used by javascript/HelloCities and other samples), including AzureWebJobsStorage, FUNCTIONS_WORKER_RUNTIME=powershell, and DURABLE_TASK_SCHEDULER_CONNECTION_STRING.

• README.md — Updated Quick Run step 3 to note that local.settings.json is included and pre-configured, so users don't need manual connection string setup.