feat: Add --suffix CLI option to control package name suffix

[mairas]

Problem

The package naming currently enforces a -container suffix via compute_package_name(). While this makes sense for most container apps, some packages need different naming:

• halos-core-containers - Infrastructure package that shouldn't have double suffix
• Future packages that may need custom suffixes or no suffix

Current Behavior

$ generate-container-packages --prefix halos apps/core-containers
Package name: halos-core-containers-container  # Wrong

Proposed Solution

Add --suffix CLI option:

# Default behavior (backwards compatible)
generate-container-packages --prefix halos apps/myapp
# -> halos-myapp-container

# Custom suffix
generate-container-packages --prefix halos --suffix service apps/myapp
# -> halos-myapp-service

# No suffix
generate-container-packages --prefix halos --suffix "" apps/core-containers
# -> halos-core-containers

Implementation

The compute_package_name() function already supports a suffix parameter - just need to expose it in the CLI.

In cli.py:

parser.add_argument(
    "--suffix",
    metavar="SUFFIX",
    default="container",
    help="Package name suffix (default: 'container', use '' for no suffix)",
)

And pass it through to load_app_definition() → compute_package_name().