Remove non-hatlabs packages from legacy stable/main

[mairas]

Description

Clean up legacy stable/main and unstable/main repositories to contain only Hat Labs product packages.

Packages to Remove

• casaos-*
• cockpit-* (except if classified as hatlabs)
• runtipi-*

Packages to Keep

• HALPI2-daemon
• HALPI2-firmware

Implementation

• Manual removal from pool/stable/main and pool/unstable/main
• Regenerate Packages files
• Verify legacy repositories still work for existing users

Acceptance Criteria

• Only Hat Labs products remain in stable/main
• Only Hat Labs products remain in unstable/main
• Legacy APT sources still work
• Removed packages available in distro-specific repos

Dependencies

• Remove non-hatlabs packages from legacy stable/main #38 (all repos updated)

Implementation Requirements

MANDATORY: Follow halos-distro/docs/DEVELOPMENT_WORKFLOW.md during implementation.

Related to #28