chore(template): auto-start apps on deploy via lifecycle.started (#454)

Add `lifecycle.started: true` to the scaffolded `databricks.yml` so a
deploy leaves the app running and returns its URL, with no separate
start step. Update the template README to use the single
`databricks apps deploy` command instead of the `bundle deploy` +
`bundle run` two-step.

Resolves the friction where a scaffolded app required a manual
`bundle run` / `apps start` after deploy.

Co-authored-by: Isaac

Author: pkosiec

template/README.md

@@ -151,37 +151,27 @@ targets:
 
 Make sure to replace all placeholder values in `databricks.yml` with your actual resource IDs.
 
-### 2. Validate Bundle
+### 2. Deploy
 
-```bash
-databricks bundle validate
-```
-
-### 3. Deploy
-
-Deploy to the default target:
+Deploy and start the app with a single command:
 
 ```bash
-databricks bundle deploy
+databricks apps deploy
 ```
 
-### 4. Run
-
-Start the deployed app:
-
-```bash
-databricks bundle run <APP_NAME> -t dev
-```
+`databricks apps deploy` validates the project, deploys it, starts the app, and prints its URL.
 
 ### Deploy to Production
 
 1. Configure the production target in `databricks.yml`
 2. Deploy to production:
 
 ```bash
-databricks bundle deploy -t prod
+databricks apps deploy -t prod
 ```
 
+> **Restarting a stopped app:** apps stop after a period of inactivity. To start one again without redeploying, run `databricks apps start <APP_NAME>`.
+
 ## Project Structure
 
 ```

template/databricks.yml.tmpl

@@ -13,6 +13,10 @@ resources:
       description: "{{.appDescription}}"
       source_code_path: ./
 
+      # Start the app automatically on deploy.
+      lifecycle:
+        started: true
+
 {{- if or .plugins.genie .plugins.files .plugins.serving}}
       user_api_scopes:
 {{- if .plugins.genie}}