Accidental deletion caused by undocumented --name default in app delete command #6048

Description:
The copilot app delete documentation on the official docs site does not clearly mention that the --name flag is required to avoid deleting the default app. This led to an accidental deletion of services from the wrong app due to misunderstanding the command syntax.

Details:

Copilot version: v1.34.1

OS/Arch: macOS / arm64

Command used: copilot app delete example-app

App type: Multi-service app with multiple environments (exp,development,etc.)

Manifest: N/A (issue with CLI usage and docs)

Observed result:

Running:
copilot app delete example-app

initiated deletion of the default app instead of example-app, because the --name flag was not used. This was unexpected, as the documentation does not clearly indicate that --name is mandatory to avoid deleting the wrong app.

Only after running copilot app delete --help did I realize that it uses the default app if --name is not specified: -n, --name string Name of the application. (default "flywheel")

Expected result:

I expected that:

Either the CLI would throw an error due to a positional argument

Or the documentation would clearly warn that not using --name will default to deleting flywheel

Debugging:

Referred to the CLI help using copilot app delete --help, which shows the default behavior 

Checked the official docs page: https://aws.github.io/copilot-cli/docs/commands/app-delete/

Did not find any clear warning about this default behavior

Suggested Fix:

Add a clear warning to the docs page:

⚠️ If you do not provide the --name flag, Copilot defaults to deleting the default app. Always use --name <app-name> to avoid accidental deletion.