Full rebuild validation and testing

[mairas]

Description

Trigger full rebuild and verify all routing rules work correctly.

Test Scenarios

1. Trigger manual full rebuild
2. Verify all 7+ repositories discovered
3. Verify all packages routed correctly
4. Count packages in each distribution
5. Verify no duplicate packages

Expected Package Distribution

• stable/main: 2 packages (HALPI2 only)
• trixie-stable/main: ~5-10 packages
• trixie-stable/hatlabs: ~2 packages

Acceptance Criteria

• Full rebuild succeeds without errors
• All packages routed correctly
• Package counts match expectations
• No packages in wrong distributions
• APT sources work for all distributions

Dependencies

• Full rebuild validation and testing #39 (legacy cleanup complete)

Implementation Requirements

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

Related to #28