app.config block does not generate app.yaml during bundle deploy

[ncf5031]

The bundle resources documentation states:

config — App configuration commands and environment variables. When specified, this configuration is written to an app.yaml file in the source code path during deployment. This allows you to define app configuration directly in the bundle YAML instead of maintaining a separate app.yaml file.

However, when using the config block on an app resource, databricks bundle deploy does not generate an app.yaml file — neither locally in the source_code_path nor in the workspace. The app starts with no environment variables set.

Reproduction
CLI version: v0.292.0

Cloud: Azure Databricks

Bundle target mode: development

databricks.yml

bundle:
  name: my-app
  databricks_cli_version: ">=0.283.0"

variables:
  catalog_name:
    description: Unity Catalog name
  warehouse_id:
    description: SQL Warehouse ID

sync:
  include:
    - backend/static/**
    - backend/app.yaml

resources:
  apps:
    my_app:
      name: my-app
      source_code_path: ./backend
      config:
        command: ["uvicorn", "app:app"]
        env:
          - name: MY_CATALOG
            value: ${var.catalog_name}
          - name: MY_WAREHOUSE
            value: ${var.warehouse_id}
          - name: MY_JOB_ID
            value: ${resources.jobs.my_job.id}

      resources:
        - name: my-job
          job:
            id: ${resources.jobs.my_job.id}
            permission: CAN_MANAGE_RUN
        - name: sql-warehouse
          sql_warehouse:
            id: ${var.warehouse_id}
            permission: CAN_USE

  jobs:
    my_job:
      name: My Job
      tasks:
        - task_key: run
          spark_python_task:
            python_file: backend/jobs/run.py
            source: WORKSPACE
          environment_key: default
      environments:
        - environment_key: default
          spec:
            environment_version: "2"
            dependencies:
              - databricks-sdk==0.78.0

targets:
  dev:
    mode: development
    default: true
    workspace:
      host: https://adb-xxxxx.azuredatabricks.net/
    variables:
      catalog_name:
        default: my_catalog
      warehouse_id:
        default: abc123

No backend/app.yaml file exists, the expectation is that the config block generates it.

Steps

databricks bundle validate -t dev   # passes with no errors
databricks bundle deploy -t dev     # completes successfully

Expected behavior
After deploy:

1. backend/app.yaml is generated locally with resolved values
2. The file is uploaded to the workspace at the app's source code path
3. The app starts with the configured environment variables

Actual behavior

• No app.yaml is generated locally
• No app.yaml exists in the workspace (workspace export returns "Path doesn't exist")
• The app starts with no environment variables set
• databricks apps get my-app shows no config or effective_config field
• bundle validate and bundle deploy produce no errors or warnings about the config block
• Additional context
• The config block is silently ignored, no error, no warning
• bundle validate accepts the config block without complaint

Additional context

• The config block is silently ignored, no error, no warning
• bundle validate accepts the config block without complaint
• This feature was introduced in CLI 0.283.0 per the resources documentation
• Workaround: maintain a separate app.yaml file manually with valueFrom references