Destructive commands exit 0 without deleting anything when there is no terminal #338

Problem

source delete, destination delete, connection delete, transformation delete and issue dismiss confirm with fmt.Scanln and discard its error:

pkg/cmd/connection_delete.go:69-78 (the other four are identical in shape):

if !cc.force {
    fmt.Printf("\nAre you sure you want to delete connection '%s' (%s)? [y/N]: ", connectionName, connectionID)
    var response string
    fmt.Scanln(&response)          // error discarded
    if response != "y" && response != "Y" {
        fmt.Println("Deletion cancelled.")
        return nil                 // exit 0
    }
}

Without a terminal, Scanln fails immediately, response stays "", and the command prints Deletion cancelled. and returns nil. A CI job that deletes nothing therefore exits 0 and looks like a success.

This is worse than crashing: the pipeline is green, and the resource is still there.

Reproduction

$ hookdeck gateway source delete src_abc123 < /dev/null
Are you sure you want to delete source 'x' (src_abc123)? [y/N]:
Deletion cancelled.
$ echo $?
0

Fix

A shared confirm helper: if stdin is not a terminal and --force was not passed, fail with a non-zero exit naming --force. All five commands already have --force, so the non-interactive path exists — it just was not required. Interactive behaviour is unchanged.

Fixed in the v2.5.0 branch alongside #333/#334/#337.