System controller crashing on site delete (using reload-type: auto)

[fgiorgetti]

Describe the bug
Deleting a podman site using skupper --platform podman site delete <name> with the system controller running using the auto reload type, is crashing the system controller container.

2026/06/09 15:36:05 INFO Stopping namespace controller component=namespaces.handler namespace=default
panic: close of closed channel

goroutine 206 [running]:
github.com/skupperproject/skupper/internal/nonkube/controller.(*NamespaceController).Stop(...)
	/go/src/app/internal/nonkube/controller/namespace_controller.go:74
github.com/skupperproject/skupper/internal/nonkube/controller.(*NamespacesHandler).OnRemove(0xc000381920, {0xc000346f40, 0x1a})
	/go/src/app/internal/nonkube/controller/namespaces.go:139 +0x34d
github.com/skupperproject/skupper/internal/filesystem.(*FileWatcher).dispatchTriggers.func1()
	/go/src/app/internal/filesystem/file_watcher.go:151 +0x2b
created by github.com/skupperproject/skupper/internal/filesystem.(*FileWatcher).dispatchTriggers in goroutine 14
	/go/src/app/internal/filesystem/file_watcher.go:150 +0x179

How To Reproduce

1. Install the system controller using reload type auto: skupper --platform podman system install --reload-type auto
2. Create a podman site: skupper --platform podman site create mysite
3. Delete the site using: skupper --platform podman site delete mysite

Environment details

• Version: v2-dev
• Platform: podman or docker