feat: configure automatic DTS/Azure Storage switching and fix task hub naming

- Add app settings override for automatic environment switching
  * Local: uses azureStorage with AzureWebJobsStorage (via host.json)
  * Azure: uses azureManaged with DTS_CONNECTION_STRING (via app settings)
  * No manual host.json changes required between environments

- Fix task hub naming convention
  * Remove hyphen from taskhub abbreviation (taskhub- → taskhub)
  * Task hub names must be alphanumeric only per Azure DTS requirements
  * Prevents 'Invalid table name' errors in production

- Clean up environment variables
  * Remove DURABLE_TASK_STORAGE_TYPE from local.settings files
  * Remove DURABLE_TASK_CONNECTION_STRING_NAME from local.settings files
  * Update generate-settings scripts to exclude removed variables

- Infrastructure improvements
  * Quote app settings keys with double underscores in bicep
  * Maintain Always Ready configuration for DTS with Flex Consumption
  * Configuration: AzureFunctionsJobHost__extensions__durableTask__storageProvider__*

This implementation follows the Azure Functions app settings override pattern
documented at: https://learn.microsoft.com/azure/azure-functions/functions-host-json\#override-hostjson-values

Author: dbarkol

infra/abbreviations.json

@@ -133,5 +133,5 @@
     "webSitesFunctions": "func-",
     "webStaticSites": "stapp-",
     "dts": "dts-",
-    "taskhub": "taskhub-"
+    "taskhub": "taskhub"
 }

infra/main.bicep

@@ -230,6 +230,9 @@ module api './app/api.bicep' = {
       AZURE_CLIENT_ID: apiUserAssignedIdentity.outputs.clientId
       DTS_CONNECTION_STRING: 'Endpoint=${dts.outputs.dts_URL};Authentication=ManagedIdentity;ClientID=${apiUserAssignedIdentity.outputs.clientId}'
       TASKHUB_NAME: dts.outputs.TASKHUB_NAME
+      // Override host.json durableTask storageProvider for Azure (use DTS instead of azureStorage)
+      'AzureFunctionsJobHost__extensions__durableTask__storageProvider__type': 'azureManaged'
+      'AzureFunctionsJobHost__extensions__durableTask__storageProvider__connectionStringName': 'DTS_CONNECTION_STRING'
     }
   }
   dependsOn: [

scripts/generate-settings.ps1

@@ -25,8 +25,8 @@ $settingsJson = @"
     "AzureWebJobsSecretStorageType": "files",
     "FUNCTIONS_WORKER_RUNTIME": "python",
     "PYTHON_ENABLE_WORKER_EXTENSIONS": "True",
-    "DTS_CONNECTION_STRING": "Endpoint=http://localhost:8080;Authentication=None",
     "TASKHUB_NAME": "default",
+    "DTS_CONNECTION_STRING": "Endpoint=http://localhost:8080;Authentication=None",
     "COSMOS_DATABASE_NAME": "dev-snippet-db",
     "COSMOS_CONTAINER_NAME": "code-snippets",
     "BLOB_CONTAINER_NAME": "snippet-backups",

scripts/generate-settings.sh

@@ -19,8 +19,8 @@ cat > src/local.settings.json << EOF
     "AzureWebJobsSecretStorageType": "files",
     "FUNCTIONS_WORKER_RUNTIME": "python",
     "PYTHON_ENABLE_WORKER_EXTENSIONS": "True",
-    "DTS_CONNECTION_STRING": "Endpoint=http://localhost:8080;Authentication=None",
     "TASKHUB_NAME": "default",
+    "DTS_CONNECTION_STRING": "Endpoint=http://localhost:8080;Authentication=None",
     "COSMOS_DATABASE_NAME": "dev-snippet-db",
     "COSMOS_CONTAINER_NAME": "code-snippets",
     "BLOB_CONTAINER_NAME": "snippet-backups",

src/local.settings.example.json

@@ -4,8 +4,8 @@
     "AzureWebJobsStorage": "UseDevelopmentStorage=true",
     "FUNCTIONS_WORKER_RUNTIME": "python",
     "PYTHON_ENABLE_WORKER_EXTENSIONS": "True",
-    "DTS_CONNECTION_STRING": "Endpoint=http://localhost:8080;Authentication=None",
     "TASKHUB_NAME": "default",
+    "DTS_CONNECTION_STRING": "Endpoint=http://localhost:8080;Authentication=None",
     "COSMOS_DATABASE_NAME": "dev-snippet-db",
     "COSMOS_CONTAINER_NAME": "code-snippets",
     "BLOB_CONTAINER_NAME": "snippet-backups",